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Nonsuch Primary School Calculation Policy 1 11 21 31 41 51 61 71 81 91 2 12 22 32 42 52 62 72 82 92 3 13 23 33 43 53 63 73 83 93 4 14 24 34 44 54 64 74 84 94 5 15 25 35 45 55 65 75 85 95 6 16 26 36 46 56 66 76 86 96 7 17 27 37 47 57 67 77 87 97 8 18 28 38 48 58 68 78 88 98 9 19 29 39 49 59 69 79 89 99 10 20 30 40 50 60 70 80 90 100 101 111 121 131 141 151 161 171 181 191 102 112 122 132 142 152 162 172 182 192 103 113 123 133 143 153 163 173 183 193 104 114 124 134 144 154 164 174 184 194 105 115 125 135 145 155 165 175 185 195 106 116 126 136 146 156 166 176 186 196 107 117 127 137 147 157 167 177 187 197 108 118 128 138 148 158 168 178 188 198 109 119 129 139 149 159 169 179 189 199 110 120 130 140 150 160 170 180 190 200 201 211 221 231 241 251 261 271 281 291 202 212 222 232 242 252 262 272 282 292 203 213 223 233 243 253 263 273 283 293 204 214 224 234 244 254 264 274 284 294 205 215 225 235 245 255 265 275 285 295 206 216 226 236 246 256 266 276 286 296 207 217 227 237 247 257 267 277 287 297 208 218 228 238 248 258 268 278 288 298 209 219 229 239 249 259 269 279 289 299 210 220 230 240 250 260 270 280 290 300 Kate Mole Nonsuch Primary School 2014 Page 1 Introduction One of the aims of the Primary Mathematics Curriculum 2014 is: To become fluent in the fundamentals of mathematics, including through varied and frequent practice with increasingly complex problems over time, so that pupils develop conceptual understanding and the ability to recall and apply knowledge rapidly and accurately. In short, this means that children need to know not just what to do, but why they are doing it. At Nonsuch, our aim is that all pupils will develop arithmetic proficiency – they will be able to do maths easily and at speed. Arithmetic proficiency does not come from simply committing number facts and procedures to memory, but from a growing understanding of numbers and the relationships between them. This policy, and the teaching of calculation throughout the school, focuses on developing procedural fluency AND the conceptual understanding in parallel. Procedural fluency is knowledge of procedures, knowledge of when and how to use them appropriately, and skill in performing them flexibly, accurately and efficiently. Conceptual understanding is comprehension of mathematical concepts which are developed through establishing connections between procedures, manipulatives (hands on practical resources), visual representations (images and pictures) and prior knowledge. Teaching of calculation Mental strategies: Written methods of calculations are based on mental strategies. Each of the four operations builds on mental skills which children must have a secure grasp of in the Early Years and Key Stage 1. Jottings and informal methods: Mental strategies provide the foundation for jottings and informal written methods of recording which are taught in Key Stage 1. Skills need to be taught in a way that will give the pupils conceptual understanding in Kate Mole Nonsuch Primary School 2014 Page 2 addition to procedural knowledge. They need to be practised and reviewed regularly. Formal written methods: The above skills lead on to formal written methods of calculation which are taught from Year 3 upwards. Formal written methods (or laying calculations out in a columnar format) must not occur in Key Stage 1. Again, the teaching of formal written methods should be taught in a way that will give the pupil secure conceptual understanding in addition to procedural knowledge. The aim of this policy is to inform teaching staff and parents of: The progression in the teaching of calculations from Reception to Year 6 The methods that will be used to teach calculation of the four operations The importance of developing procedural fluency AND conceptual understanding in parallel How to develop procedural fluency and conceptual understanding in parallel Strategies and methods for mental and written calculation need to be supported by familiar manipulatives (hands on practical equipment) and visual representations, in order to develop conceptual understanding at the same time as procedural fluency. Throughout this document, teaching strategies and methods will include the use of a variety of manipulatives and visual representations. These (or any other relevant manipulatives and / or visual representation) MUST be used when teaching and modelling methods of mental and written calculation, AND they must be accessible to ALL children during independent or guided learning. Kate Mole Nonsuch Primary School 2014 Page 3 The following strategies will be used to teach all four operations and will be referred to throughout this policy: Number Rods Number rods are used to represent numbers. They: Have a strong visual and tactile appeal that relates well to how pupils learn; Can be thought of as coloured bits of a number line that you can move around; Are powerful images that support pupils to make relationships between and within number more noticeable. Pupils can use the number rods to demonstrate concretely what they are trying to say about numbers. For example, when calculating 47 ÷ 5, a pupil explores how many 5s make 47 (a grouping model). By placing yellow rods (which represent 5) along a number line, they can demonstrate that nine 5s make 45 and there is a remainder of 2. Bar Models A bar model is a pictorial representation of a calculation problem that helps a pupil to visualise the problem and to identify where the unknown quantity is. It enables the pupils to consolidate or manipulate the information given in the problem and to understanding the mathematical concepts and relationships contained in it. The pupils draw a bar model to visualise the calculation and then use number rods or Base 10 apparatus alongside written methods to calculate the answer. Three steps are taken to ensure that the bar model is understood by the pupils. Please note that the unknown is always drawn in a dotted line. Step 1 The bar model is a pictorial representation of the number rods. It is important that the pupils draw each bar individually so that the mathematical relationships in the problem are clear. Kate Mole Nonsuch Primary School 2014 Page 4 10 – 6 = ? Step 2 The bar model is a pictorial representation of the calculation. 876 – 675 = ? Step 3 The bar model is a pictorial representation of a problem. A book has 876 pages. If you read 675 pages, how many pages do you still have to read? By drawing a model, pupils can see a problem clearly and solve it effectively. Kate Mole Nonsuch Primary School 2014 Page 5 Regrouping The term ‘regrouping’ will be used to ensure consistency of language throughout the school in all four strands of calculation. Regrouping emphasises that the value of a number has not changed. For example, when a pupil regroups 12 ones to 1 ten and 2 ones the value of the number has not changed; the number has just been regrouped in a different way. In the process of solving a calculation, base 10 apparatus or place value counters are manipulated in order to move information around, enabling the pupils to understand the relationship between hundreds, tens and ones when re-grouping to solve a calculation. Kate Mole Nonsuch Primary School 2014 Page 6 Use of place value mats, partitioning mats and calculation mats to support calculation Mats of different sorts give pupils a framework and structure within which to work. They can set out the steps for pupils to take them through the process of going from a symbolic representation of a calculation (a number or number sentence), to manipulating hands on resources to aid understanding, to being able to achieve the objective. Partitioning mat Number rods (or base 10 equipment) are used as a manipulative to give the children conceptual understanding and secure knowledge of place value in addition to procedural knowledge. Progression: The expectation is that the majority of pupils will move through the progressive stages in calculation at broadly the same pace. However, decisions about when to progress should always be based on the security of the pupils’ understanding and their readiness to progress to the next stage. The progression in this document is outlined in year groups, based on the expectations and progression in the Primary National Curriculum for Mathematics 2014. Kate Mole Nonsuch Primary School 2014 Page 7 Counting Counting should take place in every year group for 3 minutes per day. This does not have to be during the maths lesson. Ideas for counting are provided to all teachers. The use of counting sticks, hundred squares and other manipulatives and visual representations are encouraged. The statutory requirements are outlined below but other forms of counting (e.g. around the clock, using money, with decimals and percentages) should also be delivered during daily counting sessions. Year 1 Number and place value (statutory requirements) -count to and across 100, forwards and backwards, beginning with 0 or 1, or from any given number -count, read and write numbers to 100 in numerals, count in different multiples including ones, twos, fives and tens Year 2 Number and place value (statutory requirements) -count in steps of 2, 3, and 5 from 0, and count in tens from any number, forward or backward Year 3 Number, place value and rounding (statutory requirements) -count from 0 in multiples of 4, 8, 50 and 100; finding 10 or 100 more or less than a given number -count up and down in tenths; recognise that tenths arise from dividing an object into 10 equal parts and in dividing one-digit numbers or quantities by 10 Year 4 Number, place value and rounding (statutory requirements) -count in multiples of 6, 7, 9, 25 and 1000 -count backwards through zero to include negative numbers -count up and down in hundredths; recognise that hundredths arise when dividing an object by a hundred and dividing tenths by ten Year 5 Number, place value, approximation and estimation (statutory requirements) -count forwards or backwards in steps of powers of 10 for any given number up to 1 000 Kate Mole Nonsuch Primary School 2014 Page 8 Addition Manipulatives and Images Counting apparatus Number rods Base 10 equipment Place Value counters Place value cards Number tracks Numbered number lines Marked but unnumbered number lines Empty number lines Hundred square Counting stick Bead string Models and Images charts ITPs – Number Facts, Ordering Numbers, Number Grid, Counting on and back in ones and tens The bar model for addition Can you draw me a bar model to represent the question/ calculation? e.g. Kate Mole Nonsuch Primary School 2014 Page 9 Reception Recognise numerals 0 to 10 and understand the meaning of each number by recognising and knowing the number rods Count reliably up to 10 everyday objects Find one more than a number One more than three is four What is the number after…? The number after three is four Recognise numerals up to 20 and understand the meaning of each number by recognising and knowing the number rods Count in ones as they become more familiar with using numbers on a numberline and 100 square Kate Mole Nonsuch Primary School 2014 Page 10 Begin to relate addition and combing two groups of objects Begin to use the + and = signs to record mental calculations in a number sentence Children begin to solve problems using doubling Children show mental recall of number bonds to 10 and use these for problem solving. Some children show mental recall of number bonds to 20 Year 1 Continue with the use of number rods in order for children to consolidate their understanding of the value of numbers and for them to develop the skills of partitioning numbers in different ways Can you order the rods from smallest to largest? How many white rods do you think will fit along a yellow rod? How many white rods will fit along a dark green rod? Can you find the purple and green rod? Put them together and find the rod that is the same size. We can partition the black into purple and green (then attribute numbers) Kate Mole Nonsuch Primary School 2014 Page 11 Know by heart all pairs of numbers with a total of 10 and 20 Know that addition can be done in any order When adding mentally put the biggest number first and count on Progression in difficulty when adding on a number line – circle number that you are starting from and cross out in the calculation 1 digit + 1 digit Kate Mole Nonsuch Primary School 2014 Page 12 2 digits + 1 digit 2 digits + 2 digits Note: for this method to be successful and embedded, children must be able to add 10 and 1 from any given number using their knowledge of place value and having had plenty of experience with jumping in ones and tens on a 100 square. Begin to partition numbers in order to add two 2 digit numbers Kate Mole Nonsuch Primary School 2014 Page 13 Year 2 Continue with the use of number rods in order for children to consolidate their understanding of the value of numbers and for them to develop the skills of partitioning numbers in different ways. Can you order the rods from smallest to largest? How many white rods do you think will fit along a yellow rod? How many white rods will fit along a dark green rod? Can you find the purple and green rod? Put them together and find the rod that is the same size. We can partition the black into purple and green (then attribute numbers) Continue to practise the mental recall of all pairs of number bonds with a total of 10 and 20 Kate Mole Nonsuch Primary School 2014 Page 14 Know which digit changes when adding 1s or 10s to any number Continue with partitioning two digit numbers into their tens and ones and extend to partition three digit numbers into their H T and O Kate Mole Nonsuch Primary School 2014 Page 15 In Year 2 pupils learn to add using a blank numberline. They will record this in their maths book and will draw the blank numberline themselves. They should not use a ruler to draw the line. Progression in difficulty when adding on a blank numberline. Kate Mole Nonsuch Primary School 2014 Page 16 5. Bridging through 10 – add tens first then ones 47 + 28 +20 +5 +3 47 Kate Mole Nonsuch Primary School 67 2014 70 Page 17 Year 3, 4, 5 and 6 Formal written methods - Column method for addition Note that the number line method should still be modelled as part of a mental maths strategy. Pupils should progress to be able to add mentally as they are then able to visualise a numberline in their head. Begin with teaching this method without ‘carrying’ ‘Regrouping’ should be used as per the introduction to this policy, before numbers are ‘carried’ into the next column Carried digits are recorded below the line using the words ‘carry ten’ or ‘carry one hundred’, not ‘carry one’ At each stage children ‘do then record’ before moving onto the next stage / column. Pupils should never complete the whole calculation practically without recording, or complete the whole calculation in a recorded format without ‘doing’ Children need to be careful how they set out the numbers when calculating, especially with decimals In Year 3 children should be taught to add numbers with up to 3 digits using a Calculation Mat and Base 10 equipment. Children should use equipment during independent and guided learning. In Year 4 children should be taught to add numbers with up to 4 digits using a Calculation Mat and Base 10 equipment, moving onto place value counters. In Year 5 children should be taught to add whole numbers with more than 4 digits, modelled by the teacher using Base 10 equipment / Place Value Counters. Children may choose or choose not to use equipment during independent learning. Children who are not working at the Year 5 level should use equipment to develop their conceptual understanding. In Year 6 children should develop and secure their understanding when adding numbers with more than 4 digits and those including decimals. Kate Mole Nonsuch Primary School 2014 Page 18 Progression in the formal written method for addition 2 digits + 2 digits / 3 digits + 3 digits with no carrying into the tens column. 32 + 25 Bar model: 1. Do: Lay out on the calculation mat with Base 10 and record the calculation at the side 2. Do: add the ones by combining the 2 and 5 ones. Record. 3. Do: add the tens by combining the 3 tens and 2 tens. Record. 2 digit + 2 digit / 3 digit + 3 digit with carrying into the tens column. 47 + 5 Bar model: Kate Mole Nonsuch Primary School 2014 Page 19 1. Do: Lay out on the calculation mat with Base 10 and record the calculation at the side 2. Do: Add the units by combining the 7 and 5 ones to make 12 ones 3. Do: Regroup 10 ones as 1 ten and then carry into the 10s column. Record. 2 digits + 2 digits / 3 digits + 3 digits with carrying into the tens and hundreds column. 77 + 45 Bar Model: Kate Mole Nonsuch Primary School 2014 Page 20 1. Do: Layout out on the calculation mat with Base 10 and record the calculation at the side 2. Do: 5 ones plus 7 ones equal 12 ones so they need to be regrouped into 1 ten and 2 ones.’ Carry’ the ten into the tens column. Record. 3. Do: 7 tens plus 4 tens, plus the 1 ten we carried, equal 12 tens so they need to be regrouped into 1 hundred and 2 tens. ‘Carry’ the hundred into the hundred column. Record. Kate Mole Nonsuch Primary School 2014 Page 21 The above teaching strategies are used to teach the following calculations. Pupils should draw a bar model to represent the calculation / problem at all stages. From Year 4 upwards, once children are secure with the use of Base 10 equipment to ensure conceptual understanding, place value counters can be used. 676 + 558 676 + 558 1234 1 1 Column addition with decimals In the following examples pupils need to understand that the decimal points are always written underneath each other when using column addition. Pupils should have a secure understanding of place value in order to be successful. Adding amounts of money provides a useful context within which to teach the addition of decimals. A calculation mat for money supports conceptual understanding. Kate Mole Nonsuch Primary School 2014 Page 22 12.5 + 23.7 36.2 12.5 + 23.7 1 123.5 + 24.6 123.5 + 24.6 148.1 1 34.5 + 27.43 34.50 + 27.43 61.93 1 Kate Mole Nonsuch Primary School 2014 Use zero as a place holder Page 23 Subtraction Mental skills Recognise the size and position of numbers Count on or back in ones and tens Know number facts for all numbers to 20 Subtract multiples of 10 from any number Partition and recombine numbers (only the number to be subtracted) Bridge through 10 Manipulatives and Images Counting apparatus Number rods Place value apparatus Base 10 equipment Place value counters Number tracks Numbered number lines Marked but unnumbered numberlines Hundred squares Empty numberlines (not to be drawn with a ruler) Counting stick Bead strings ITPs – Number facts, counting on and back in ones and tens, Difference Bar Model for subtraction Kate Mole Nonsuch Primary School 2014 Page 24 Reception Begin to count backwards in familiar contexts such as number rhymes or stories Continue to count back in ones from any given number Begin to relate subtraction to ‘taking away’ Kate Mole Nonsuch Primary School 2014 Page 25 Find one less than any given number What is the number before 6? Count back in ones Year 1 Begin to use the – and = signs to record mental calculations in a number sentence Kate Mole Nonsuch Primary School 2014 Page 26 Know by heart subtraction for numbers up to 20 Subtract single digit numbers by counting back along a marked number line. Kate Mole Nonsuch Primary School 2014 15 – 8 = 7 Page 27 Begin to find the difference by counting on from the smallest number Use number rods to calculate the difference: What’s the difference between 8 and 10? The difference is 2. Count along a number line from the smallest number to the largest number (summer term). Also show with number rods as a practical support. 15 – 7 = 8 Year 2 – subtracting using a numberline Partition one and two digit numbers using partitioning mats and apparatus. Kate Mole Nonsuch Primary School 2014 Page 28 Subtract one from any given number and know which digit changes . Subtract ten from any given number and know which digit changes. 18 – 1 = 17 28 – 10 = 18 Use a blank numberline to subtract numbers that do not bridge through 10. Partition the number to be subtracted. Children jump back in tens and ones. For this to be successful, children must be confident with the above. Kate Mole Nonsuch Primary School 2014 22 Page 29 Use a blank numberline to subtract numbers that bridge through 10. Partition the number to be subtracted. Children jump back in tens and ones (they may combine their jumps). 74 – 27 = 47 Use a blank numberline to find the difference – how many numbers are in between? 29 Year 3, 4, 5 and 6 Formal written methods - Column method for subtraction Note that the number line method should still be modelled as part of a mental maths strategy. Pupils should progress to be able to subtract mentally as they are then able to visualise a numberline in their head. When calculating with time and finding time differences, the numberline method should be used EVERY TIME. Begin with teaching this method without ‘carrying’ ‘Regrouping’ should be used as per the introduction to this policy At each stage children ‘do then record’ before moving onto the next stage / column. Pupils should never complete the whole Kate Mole Nonsuch Primary School 2014 Page 30 calculation practically without recording, or complete the whole calculation in a recorded format without ‘doing’ Children need to be careful how they set out the numbers when calculating, especially with decimals Children should be encouraged to use inverse operations to check if their answer is correct. This gives them the opportunity to practise both operations (addition and subtraction) at the same time. Explicit teaching needs to point out that if they add the bottom number to the answer they should end up with the number they started with. Always support with Base 10 equipment to secure conceptual understanding. In Year 3 children should be taught to subtract numbers with up to 3 digits using a Calculation Mat and Base 10 equipment. Children should use equipment during independent and guided learning. In Year 4 children should be taught to subtract numbers with up to 4 digits using a Calculation Mat and Base 10 equipment, moving onto place value counters. In Year 5 teaching should be taught to subtract whole numbers with more than 4 digits, modelled by the teacher using Base 10 equipment / Place Value Counters. Children may choose whether or not to use equipment during independent learning. Children who are not working at the Year 5 level should use equipment to develop their conceptual understanding. In Year 6 children should develop and secure their understanding when subtracting numbers with more than 4 digits and those including decimals. Kate Mole Nonsuch Primary School 2014 Page 31 2 digits - 2 digits / 3 digits - 3 digits with no regrouping. Model writing in both the horizontal and vertical forms. 37 – 16 37 -16 Bar model: 1. Do: Lay out on the calculation mat with Base 10 and record the calculation at the side. 2. Do: Subtract 6 ones and remove them. Record. 3. Do: subtract 1 ten and remove it. Record. How many are left? Kate Mole Nonsuch Primary School 2014 Page 32 2 digits - 2 digits / 3 digits - 3 digits with regrouping tens into 10 ones. 432 - 124 bar model: 1. Do: Lay out 432 on the calculation mat with Base 10 and record the calculation at the side 2. Do: discuss how 4 ones cannot be subtracted from 2 ones. Regroup a ten as 10 ones and place in the ones column. Record. 3. Do: subtract the units – remove them. Record. 4. Do: subtract the tens – remove them. Record. 5. Do: subtract the hundreds – remove them. Record. 6. Check using the inverse. Use Base 10 to support conceptual understanding Kate Mole Nonsuch Primary School 2014 Page 33 3 digits - 3 digits with regrouping the tens into ones and the hundreds into ten 10s. 532-254 = 532 - 254 Bar Model: 1. Do: Layout out on the calculation mat with Base 10 and record the calculation at the side 2. Do: discuss subtracting the ones. Regroup a ten as 10 ones. Record. 3. Do: Subtract the ones – remove them. Record. Kate Mole Nonsuch Primary School 2014 Page 34 4. Do: Discuss subtracting the tens. Regroup 1 hundred as 10 tens to make 12 tens altogether. Record. 5. Do: subtract the tens – remove them. Record. 6. Do: discuss and subtract the hundreds – remove them. Record. 7. Prove the answer is correct by using the inverse. Use Base 10 to support conceptual understanding. Pupils should draw a bar model to represent the calculation / problem at all stages. Once children are secure with the use of Base 10 equipment to ensure conceptual understanding, place value counters can be used from Year 4 upwards. Kate Mole Nonsuch Primary School 2014 Page 35 Column subtraction with decimals In the following examples pupils need to understand that the decimal points are always written underneath each other when using column subtraction. Pupils should have a secure understanding of place value in order to be successful. Subtracting amounts of money provides a useful context within which to teach the subtraction of decimals. A calculation mat for money supports conceptual understanding. £2.43 - £1.29 = 1. Do: discuss subtracting the ones. Regroup a ten as 10 ones. Record. 3 1 £2.43 - 1.29 _____ 2. Do: Subtract the ones – remove them. Record. 3 1 £2.43 - 1.29 4 Kate Mole Nonsuch Primary School 4_ 2014 Page 36 3. Do: Subtract the tens – remove them. Record. 4. Subtract the hundreds – remove them. Record. Kate Mole Nonsuch Primary School 2014 Page 37 Multiplication Mental Skills Recognise the size and position of numbers Count on in different steps 2s, 5s, 10s Double numbers up to 10 Recognise multiplication as repeated addition Quick recall of multiplication facts Use known facts to derive associated facts Multiplying by 10, 100, 1000 and understanding the effect Multiplying by multiples of 10 Models and Images Counting apparatus Base10 equipment Place Value counters Place value apparatus Arrays 100 squares Number tracks Numbered number lines Marked but unnumbered lines Empty number lines Multiplication squares Counting stick Bead strings Models and Images charts ITPs – Multiplication grid, Number Dials, Multiplication Facts Bar model for multiplication: Kate Mole Nonsuch Primary School 2014 Page 38 Year 1 Count in steps of 2s 5s and 10s forward and back from 0 and from any of its multiples using the 100 square. Take the opportunity to discuss patterns that are recognized. Other resources that aid counting 1. Using laminated sheets with circles (groups) on them, children group objects using the correct mathematical vocabulary. 2. Children begin using jottings of simple multiplication with the associated vocabulary. They begin by drawing the number of groups, then draw dots inside the circles. They count the number of dots they have altogether to get the answer. Kate Mole Nonsuch Primary School 2014 Page 39 3. Children are exposed to the different ways in which multiplication can be expressed using concrete materials and linking it to real life situations. They begin to understand that repeated addition can also be expressed as multiplication using concrete materials. Expressing multiplication as repeated addition. Use number rods to support understanding. Expressing multiplication as arrays. 4. Children begin to commit multiples of 2, 5, 10 to memory and use these facts to solve problems. There are 10 spiders. How many legs do they have altogether? 8 x 10 = 80 When Peter behaves well in school he gets 2 sweets at the end of the day. If he behaves well for 5 days, how many sweets will he get altogether? There are 4 flower beds in a garden. Each flower bed has 3 flowers. How many flowers are in the garden altogether? Kate Mole Nonsuch Primary School 2014 Page 40 Year 2 Counting Choir Count in steps of 2s, 3s, 5s, 10s and 20s forward and back from 0 and from any of its multiples using the 100 / 200 square. Take the opportunity to discuss patterns that are recognised. Know doubles and their corresponding halves. Extend to partitioning numbers, then double and halve. 1. Children continue to use jottings of simple multiplication with the associated vocabulary. Those who still find it difficult use laminated mats with circles to group concrete objects or arrays. They begin by drawing the number of groups, then draw the number of dots inside the circles. They count the number of dots they have altogether to get the answer. Kate Mole Nonsuch Primary School 2014 Page 41 2. Children use number rods as a practical way to develop understanding of multiplication as repeated addition. This also supports them in working horizontally along a number line which will then progress to jumping along numberlines in equal groups. 4 x 5 = 20 3. Teach using apparatus and jottings when multiplying multiples of 10 by putting / drawing Base 10 in each of the groups They begin by drawing the number of groups, then put / draw the 10s inside the circles. They count the number of 10s using their knowledge of counting in 10s to obtain the answer. 4. Teach jumping on a marked numberline in multiples of 2, 3, 5 and 10 This method requires children to keep the jumps equal in size as they count the number of jumps. This is a challenging process however it further embeds the understanding of repeated addition. The constant re-enforcement of vocabulary ‘groups of’ is very important. 5. As children become confident with counting in multiples of 2, 3, 5, 10, they begin to use the empty numberline to solve multiplication problems. In this method there are strong links with the activity of counting choir using the 100 / 200 squares and the recognition of patterns with each of the multiples. Children write their own number after each jump they make. Kate Mole Nonsuch Primary School 2014 Page 42 6. They further develop their skills of problem solving using multiplication and begin to relate it to the area of a rectangle / square Children investigate the number of multilink cubes needed to create a block with a given number of length and width. This further reinforces the commutative law of multiplication. Kate Mole Nonsuch Primary School 2014 Page 43 Year 3, 4, 5 and 6 Grid multiplication alongside short and long multiplication 2 digit x 1 digit (no regrouping) using apparatus. 13 x 3 Bar model 1. Do: Model how 13 can be partitioned into 10 and 3 using number rods and that we need 3 lots of these. Record this on a grid with the vertical layout .alongside. . 13 x 3 x 3 2. Do: Multiply the ones. 3 x 3 – refer to number rods and times tables facts. Record on the grid and the vertical format. x 3 3. Do: Multiply the tens. 3 x 10 – refer to number rods and times tables facts. Record on the grid and the vertical format. . 4. Do: add up the tens and ones, referring to the apparatus and the grid. 30 + 9 = 39. Record the answer on the vertical format. . x 3 Kate Mole Nonsuch Primary School x 3 2014 10 10 10 30 10 30 3 3 9 3 9 3 9 13 x 3 9 13 x 3 9 30 13 x 3 9 30 39 Page 44 2 digit x 1 digit (with regrouping) using apparatus. Note the number rods or place value counters can be used (see NCETM video) 24 x 6 Bar model 1. Do: Model how 24 can be partitioned into 20 and 4 using number rods and that we need 6 lots of these. Record this on a grid with the vertical layout alongside. x 6 2. Do: Multiply the ones. 6 x 4 = 24 – refer to number rods and times tables facts. Record on the grid and the vertical format. x 6 3. Do: Multiply the tens. 6 x 20 = 120 – refer to number rods and times tables facts. Record on the grid and the vertical format. . x 6 4. Do: add up the tens and ones, referring to the apparatus and the grid. Record the answer on the vertical format. . Kate Mole Nonsuch Primary School x 6 2014 20 20 20 120 20 120 4 4 24 24 x 6 24 x 6 24 4 24 24 x 6 24 120 4 24 24 x 6 24 120 144 Page 45 3 digits x 1 digit using place value counters. 164 x 3 Bar model 1. Do: Model how 164 can be partitioned into 100 and 60 and 4 using number place value counters and that we need 3 lots of these. Record this on a grid with the vertical layout alongside. x 3 2. Do: Multiply the ones. 3 x 4 = 12 – refer to place value counter and times tables facts. Record on the grid and the vertical format. 3. Do: Multiply the tens. 3 x 60 = 180 – refer to place value counters and times tables facts. Record on the grid and the vertical format. 100 x 3 x 3 Kate Mole Nonsuch Primary School 100 100 2014 60 4 60 60 180 164 x 3 4 12 4 12 164 x 3 12 164 x 3 12 180 Page 46 4. Do: Multiply the hundreds. 3 x 100 = 300 – refer to place value counters and times tables facts. Record on the grid and the vertical format. x 3 100 300 60 180 4 12 164 x 3 12 180 300 5. Do: add up 164 the hundreds, x 3 tens and ones, 12 referring to 180 the grid and the vertical +300 format. 492 Record the answer on the vertical format. . 2 digit / 3 digit x 2 digit – grid method alongside recording vertical format – no apparatus x 3 100 300 60 180 4 12 e.g. 43 x 24 1. Do: Multiply the ones x ones (3 x 4 = 12) Record on the grid, then ones x tens (3 x 20) Record on the grid. Model adding up along the row to record on the vertical format. Kate Mole Nonsuch Primary School x 40 3 2014 20 4 60 12 43 x 24 72 Page 47 2. Do: Multiply the tens x ones (40 x 4 = 160) Record on the grid, then tens x tens (40 x 20) Record on the grid. Model adding up along the row to record on the vertical format. x 40 3 20 800 60 4 160 12 Add 3. Do: Use column addition to add up on the vertical format. 43 x 24 72 + 960 43 x 24 72 + 960 1032 1 2 digit / 3 digit x 1 digit – short multiplication – formal written method Begin with no carrying. Note that in the KS2 National Tests, marks will not be awarded for use of the grid method. Pupils MUST use the formal written methods of short and long multiplication to be awarded the mark. Kate Mole Nonsuch Primary School 2014 Page 48 2 digit / 3 digit x 2 digit – long multiplication – formal written method Note where numbers are carried. Begin with multiplying the unit with each of the digits. Children need to be taught that the 0 in the second row is written as a placeholder because we are now multiplying the tens with each digit. Kate Mole Nonsuch Primary School 2014 Page 49 Year 3, 4, 5 and 6 Ratio How much flour will she need? Kate Mole Nonsuch Primary School 2014 Page 50 Division Mental Skills Recognise the size and position of numbers Count back in different steps 2s, 5s, 10s Halve numbers to 20 Recognise division as repeated subtraction Quick recall of division facts Use known facts to derive associated facts Divide by 10, 100, 1000 and understanding the effect Divide by multiples of 10 Models and Images Counting apparatus Arrays 100 squares Number Tracks Numbered number lines Marked but unnumbered numberlines Empty numberlines Multiplication squares Number rods Models and Images charts ITPs – Multiplication Remainders Grid, Number Dials, Grouping Bar Model for Division: 72 ÷ 8 = Kate Mole Nonsuch Primary School 2014 Page 51 Year 1 Counting Choir Count in steps of 2s, 5s and 10s forwards and back from 0 and from any of its multiples using the 100 Square and taking the opportunity to discuss patterns that are recognized . Half of 12. Share dots equally one by one Half of 6 = 3 ½ of 6 = 3 1. Children learn to share objects practically. 6 muffins shared between 3 people is 2 each 6÷3=2 2. Children use grouping to solve problems involving division. With the help of laminated sheets children place the given number of objects into groups using the correct mathematical vocabulary. Please note: to distinguish between grouping using multiplication and division a different type of grouping sheet is used as shown below. 10 cookies into groups of 2. How many groups? 10 ÷2 = 5 I have 10 cookies. Put them into groups of 2. How many groups have we got altogether? Kate Mole Nonsuch Primary School 2014 Page 52 3. Grouping with the use of jottings. Children first draw the total number of items using dots and then put circles round the given number of dots. They count the number of groups to obtain the answer. I have 12 multilink cubes. If I put them into groups of 2, how many groups have I got? Year 2 Counting Choir Count in steps of 2s, 3s, 5s, 10s and 20s forwards and back from 0 and from any of their multiples using the 100 / 200 square. Take the opportunity to discuss patterns that are recognized. Use known multiplication facts to work out corresponding division facts Know doubles and corresponding halves. Extend to partitioning numbers, then double / partitioning numbers then halve. Kate Mole Nonsuch Primary School 2014 Page 53 1. Children continue to use concrete materials and physical resources to share or group objects equally with or without the help of laminated grouping sheets. Sharing model of division: Grouping model of division 12 muffins shared between 3 people is 4 each 12 ÷ 3 = 4 I have 18 strawberries. Put them into groups of 3. How many have we got altogether? 2. Grouping with the use of jottings. Children first draw the total number of items using dots, then put circles around the given number of dots. They count the number of groups to obtain the answer. In Y2 children are exposed to grouping in all multiples between 2 and 9. I have 18 multilink cubes. If I put them into groups of 3, how many groups have I got? 3. Children begin to use a marked numberline and number rods to solve division problems. Always teach children to count on (not back) in groups. 18 ÷ 3 = Kate Mole Nonsuch Primary School 2014 Page 54 Children then move on to just using a marked numberline and counting on in groups This method requires children to find out how many jumps of 3 they can make between 0 and 18. They circle 0 and 18 on the numberline before they commence their equal jumps of 3. The constant reinforcement of vocabulary ‘into groups of’ is very important. 4. More confident children, who are reliably able to count in multiples of 2,3,5 and 10, use an empty numberline to make their jumps. Children write their own numbers underneath the numberline each time they complete a jump to keep track of where they are. The challenge in this process is to remember to stop once they get to the required number, in this case, 18. 5. Reinforce division as grouping through arrays, using number rods and jottings, and introduce remainders. Kate Mole Nonsuch Primary School 2014 Page 55 6. Children begin to use a marked numberline to solve division problems involving remainders. The challenge in this process is to remember to not carry on jumping in multiples of 5 after number 25 and to realise that the remaining jumps need to be made in jumps of ones to work out the remainder. Children must be able to count in multiples of 2, 3, 5 and 10 securely in order to use this method successfully. Kate Mole Nonsuch Primary School 2014 Page 56 Years 3, 4, 5 and 6 Short Division HTO ÷ O Children must have secure division facts knowledge to 10 x 10 in order for them to see the benefits of this quick efficient method. Those children who are not yet ready for this method should carry on with grouping through the use of arrays, numberlines and other models as demonstrated in Year 2 policy. The vocabulary may seem very advanced but it is important that it is modelled from the beginning and subsequently throughout all KS2 year groups: Divisor – the number that is being divided by; e.g. in the calculation 45 ÷ 5, 5 is the divisor . Dividend – the number that the divisor is being divided into. 45 ÷ 545 is the dividend. Quotient – the answer to a division calculation. 45 ÷5 = 9. 9 is the quotient. As children have to get used to a new layout which does not necessarily provide conceptual understanding, it is imperative that the short division method is taught using manipulatives (PV counters recommended) which shows the conceptual understanding alongside the procedural method. Click on the link below to view videos from the NCETM which very clearly demonstrate how to move to a written method of division using manipulatives which will support conceptual understanding. https://www.ncetm.org.uk/resources/43589 1. Moving to a written method of division (short division) 2. Representing division with place value counters 3. Using place value counters and recording division 4. Division with remainders 5. Division with regrouping (labelled as exchange on the video title) Kate Mole Nonsuch Primary School 2014 Page 57 Years 3, 4, 5 and 6 Long Division HTO ÷ TO Chunking method – note that this method is not accepted as an efficient written method in the KS2 national tests but is an important step in the process When children first learn to divide by a 2 digit number using chunking, provide them with a fact box. As they become more confident, they can create their own fact box if they wish. Answers are expressed as whole number remainders. 1 Fact Box 2 x 15 = 30 3 x 15 = 45 4 x 15 = 60 5 x 15 = 75 6 x 16 = 90 7 x 15 = 105 8 x 15 = 120 9 x 15 = 135 10 x 15 = 150 20 x 15 = 300 In Year 6 Children must also be taught to express the remainder as a fraction. Kate Mole Nonsuch Primary School 2014 Page 58 In Year 6 Children will also be taught the traditional ‘long division’ written method. The remainder can be expressed as a decimal (remainder or fraction). To express remainders as a decimal, we must carry on bringing down a zero until we have no remainders. Note that children in Y6 must use the traditional long division (or short division) method to gain the mark in the KS2 national tests – chunking will not be awarded a mark. Kate Mole Nonsuch Primary School 2014 Page 59