Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Multiplication Stage Foundation and stage 1 What methods do we used for multiplication? Notes Early stages of recording will be mainly pictorial, with lots of practical based activities using a range of apparatus. Children can be given objects or pictures and asked to sort or to put rings around them, to experience grouping objects in a variety of ways. 3 groups of 2 or 3 lots of 2 or Much of early maths work with multiplication will be oral, arising through play activities. In practical activities and discussion children will develop the vocabulary involved in multiplication. The concept of multiplication begins with counting patterns 2,5,10. At first, results will be recorded through photographs or pictorially, then using phrases such as ‘lots of’, 2 groups of 3 or 2 lots of 3 Stage 2 or sets of Grouping numbers When using repeated addition, pupils can combine number pairs or bigger numbers using facts already known: for example There are 12 cakes on a tray. How many rows are there if there are three cakes in each row? 3 + 3 + 3 + 3 = 12 4 rows of 3 cakes How many rows are there, if there are four cakes in each row? 4 + 4 + 4 = 12 3 rows of 4 cakes Repeated addition to model multiplication is used to consolidate the concept of ‘groups of.’ The children will experience practical activities to consolidate these concepts e.g. There are 12 cakes on a tray. How many cakes are there if there are three cakes in each row? How many rows if there are four cakes in a row? At stage 2, when deemed appropriate by the teacher, the multiplication symbol will be introduced as meaning the same as repeated addition. Derive and recall multiplication facts for the 2, 5 and 10 times tables. How many groups of six can you make? 2 lots of 6 Describing an array using practical apparatus or pictures to describe the different ways to create amounts, can help children to ‘find’ related facts, for example: 4 x 2= 8 2 x 4 = 8 Children will be strongly encourages to draw lots of. 5 x2= 5 lots of 2. The relationship between division and multiplication will be introduced as being the inverse of each other e.g. 3 x 5 = 15 15 5 = 3 or 15 3 = 5. Stage 3 In year 3, concepts learnt at year two are consolidated and extended: 4 x 3 =12 3 x 4 = 12 Using an array also assists children to recognise that multiplication can be done in any order. The relationship between division and multiplication will be consolidated as being the inverse of each other e.g. 3 x 5 = 15 15 5 = 3 or 15 3 = 5. The grid method is used to introduce partitioning using place value: How many sweets are needed for party bags if 13 children are to have 3 each? 10 3 3 30 Stage 4 9 = 39 sweets As pupils begin to work with larger numbers, they will have to use personal jottings to help break down a calculation into smaller steps. These jottings will help them to keep track of their mental calculations, explore different connections and develop a range of approaches to multiplying. A tyrannosaurus Rex was approximately 60 times long as a lizard. A lizard’s tail is 15 cm long. About how long was the tail of the dinosaur? 15 x 60 = (10 x 60) + (5 X 60) = 600 + 300 = 900 or 10 x 60 = 600 5 x 60 = 300 600 + 300 = 900 or 30 x 60 = 1800 1800 2 = 900 or 3 x 60 = 180 180 x 5 = 900 96 pears are to be sold in packets of 4. How many packets will there be? Use of mental jottings: 96 x 4 = 384 90 x 4 = 360 6 x 4 = 24 The grid method is consolidated: How many sweets are needed for party bags if 27 children are to have 6 each? 20 7 6 120 42 = 162 sweets When pupils work with numbers beyond the 10 x 10 table facts, they will have to decide which facts they need to use and which methods will be the most efficient. During stages 3 and 4, pupils will be taught additional facts and will work on different ways to derive new facts from those they already know. Written recording of related facts will help the pupils to make the connections they will need when calculating. Written recording will focus on: Gaining a good understanding of the meaning of the multiplication and the different ways results can be symbolised; Recognising that multiplication and division are inverse (opposite) operations to each other; Learning multiplication facts Making connections between numbers, e.g. 36 is a multiple of 3, 6, 9, 4, 12 and 2 Developing and refining written methods for multiplying 2-digit numbers by a single digit Children must recall facts for the 2, 3, 4, 5, 6 and 10 times tables and recognise multiples of 2, 5 or 100 up to 1000 Children must derive and multiplication facts up to 10 x 10 times tables, the corresponding multiples of numbers to 10 up to the tenth multiple. Stage 5 and 6 Multiplication with larger numbers Some pupils might want to use informal jottings, using mental strategies. Others might want to use the grid method. The class wants to make 275 spiders for a display. How many legs do they need? 275 x 8 = 2200 200 x 8 = 1600 70 x 8 = 560 5 x 8= 40 Or x8 200 70 5 1600 40 560 The written recording in these years will focus on: Making appropriate choices from a flexible range of strategies; Relating known facts to larger numbers and decimals; Establishing clear and efficient ways to record working, moving towards using standard methods 1600 + 560 + 40 = 2200 Multiplication with two and three digit numbers Pupils will use the same methods to solve problems involving numbers of this size i.e. informal jottings, grid methods or expanded layout and standard method: How many hours are there in one year? 365 x 24 300 60 5 20 6000 1200 100 4 1200 240 20 6000+1200+100= 7300 1200+240+20= 1460 8760 to 365 X 24 20 (5x4) 240 (60 x 4) 1200 (300 x 4) 7300 (365 x 20) 8760 Multiplication using decimals Written methods for decimals can be built on procedures used for whole numbers. A chicken’s egg is 5.4 cm long. If an ostrich’s egg was approximately 4 times as long, how long would it be? At stage 5, multiplication calculations will be extended to include multiplying numbers with one decimal place by a single digit, and stage 6, numbers with two decimal places by a single digit, as well as a decimal number multiplied by a decimal number. 5.4 x 4 = 5.0 x 4 = 20 cm 0.4 x 4 = 1.6 cm 20 cm + 1.6 cm = 21.6 cm What is the product of 23.1 and 1.7? 1.0 0.7 20 20 14 3 3 2.1 0.1 0.1 0.07 23.1 + 16.17 39.27 or Turn the numbers in to whole numbers, and then divide by 10. 231 x 17 If children multiply decimals out to whole numbers, they must first estimate their answer. 200 30 10 7 1 2000 300 10 1400 210 7 2310 + 1617 = 3927 3927 ÷ 100 = 39.27