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I think of a number and add 6. My answer is 17, what number did I start with? 11 Well done Chris. How did you think that through? SUMS AND THINGS FOR PARENTS! What can a numerate child do? By the age of 11 they should : have a sense of the size of number and where it fits into the number system know by heart addition and subtraction facts to 20, multiplication and division facts to 10x10, doubles and halves, complements to 100, multiply and divide by 10 and 100 use what they know to figure out answers mentally What can a numerate child do? (cont.) calculate accurately and efficiently, both mentally and on paper, using a range of strategies recognise when it is appropriate to use a calculator- and when it is not- and be able to use one effectively explain their methods and reasoning using correct mathematical terms judge whether their answers are reasonable and have strategies for checking them where necessary The aim The aim is for children to do mathematics in their heads, and if the numbers are too large, to use pencil and paper to avoid losing track. To do this children need to learn quick and efficient methods, including appropriate written methods. All of this relies on knowing number facts to prevent the need to work out each small stage. We want children to ask themselves: Can I do this in my head? Can I do this in my head using drawings or jottings to help? Do I need to use an expanded/compact written method? Do I need a calculator? ADDITION AND SUBTRACTION How do you add and subtract? 61 + 45 7800 – 5600 5735 + 3657 5735 + 3990 83 – 68 5002 – 4996 538 - 295 267 + 267 2.5 + 2.7 5.1 - 2.78 ADDITION 2+4= My Mum gives me 2 sweets and my Dad gives me 4 sweets – how many do I have altogether? 8+6= There are 8 people on the train then 6 more get on. How many people are on the train now? |||||||| |||||| ADDITION 76 + 47 = +10 76 +10 86 +10 96 +10 106 +7 116 + 40 76 123 +7 116 123 ADDITION Record steps in addition using partitioning: 14 + 22 14 + 20 = 34 34+ 2 = 36 or 14 + 22 10 + 20 = 30 4+ 2 = 6 80 + 6 = 36 ADDITION 176 + 147 = 100 + 70 + 6 + 100 + 40 + 7 200 + 110 + 13 = 323 ADDITION Have a go! 358 + 473 = SUBTRACTION Taking away Finding the difference 8–3= Gran baked 8 cakes. I ate 3 – how many were left? 2+=5 I have 2 cats but my sister has 5. How many more cats does she have? |||||||| || ||||| SUBTRACTION We can do subtraction by partitioning: 38 – 14 = 38 – 10 = 28 28 – 4 = 24 SUBTRACTION Imran has 43 conkers; he gives 24 away to his friends. How many does he have left? 43 – 24 = 19 23 -4 19 conkers 33 -10 43 -10 SUBTRACTION Sam has saved 93p, Amy has 55p. How much more money does Sam have than Amy? 93 – 55 = +5 55 38p more +30 60 +3 90 93 SUBTRACTION 8.23 – 4.55 = +0.45 4.55 3.68 5.00 +3 +0.23 8.00 8.23 SUBTRACTION A sports stadium holds 9010 spectators. 5643 people attend a football match. How many empty seats are there? + 57 5643 5700 +300 +3010 6000 9010 5643 3367 empty seats 5700 6000 9010 57 +300 +3010 3367 SUBTRACTION Example: 639 – 424 = - 600 400 200 + + 30 20 + + 9 4 + 10 + 5 = 215 SUBTRACTION Example: 491 – 155 = 80 - 11 400 + 90 + 1 100 + 50 + 5 300 + 30 + 6 8 11 491 - 155 336 SUBTRACTION Have a go! Use a number line: 97 - 68 = Use the expanded method: 639 - 291 = MULTIPLICATION MULTIPLICATION Each child has 2 legs. How many legs do 4 children have? There are 6 eggs in a box. How many in 3 boxes? ||| ||| ||| ||| ||| ||| 2 + 2 + 2 + 2 6 + 6 + 6 MULTIPLICATION MULTIPLICATION MULTIPLICATION By the end of Key Stage 1, children are expected to know their x2, x5 and x10 tables. By the end of Year 4, children should know all their times tables. This knowledge is key to them being able to multiply larger numbers with written methods. MULTIPLICATION 47 x 8 = x 8 40 320 7 56 = 376 30 1200 180 7 280 42 37 x 46 = x 40 6 = 1480 = 222 = 1702 MULTIPLICATION MULTIPLICATION MULTIPLICATION Have a go at using the grid method yourself: 43 x 59 = x 50 9 40 2000 360 3 150 27 = 2150 = 387 2537 How can you help? Talk about how you do maths Give praise and encouragement Be positive Ask your child to explain Make sure maths is fun! FURTHER READING Recommended reading: ‘Maths for Mums and Dads’ By Rob Eastaway and Mike Askew ISBN-13: 978-0224086356 .