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TEACHING WRITTEN CALCULATIONS St. Augustine’s Catholic Primary Introduction • Common approach – so the children don’t get confused • Mainly start recording fromY1 onwards • Stages relate to year groups but not all children at year group level • Cover all calculations today – am available afterwards, or speak to class teacher • Presentation on school website ADDITION Stage 1 –Teachers demonstrate number lines 8 + 5 = 13 0 1 2 3 4 5 6 7 8 9 10 11 12 13 Stage 2 – Children use empty number lines starting with the largest number and counting on 34+23 = 57 34 44 54 55 56 57 34 44 54 57 54 57 34 Stage 3 Make sure children count from largest number first. Example 38 + 86 = swap to 86 + 38 = Children begin to work in columns + 6 7 2 4 1 1 (7+4) 8 0 (60 + 9 1 20) Stage 4 – Children begin to carry below the line 7 + 8 1 8 3 4 2 2 5 Stages 5 and 6 Children use larger numbers Children use decimal numbers Have a go!! How would you use a number line to demonstrate 28 + 54 = Use the column method to calculate 345 + 67 = SUBTRACTION Stage 1 – Teachers demonstrate number lines 13 – 5 = 8 0 1 2 3 4 5 6 7 8 9 1011 12 131415 Stage 2 – Children use empty number lines 47-23 = 24 25 26 27 37 47 24 27 37 47 24 27 47 Counting on 82-47 = 47 48 49 50 60 70 80 81 82 Stage 3 – Children use column method 71 – 46 = - 7 0 1 4 0 6 Stages 4,5 and 6 – Larger numbers, leading to short method - 7 5 4 2 8 6 Have a go!! How would you use a number line to demonstrate 58 – 24 = Use the short column method to calculate 654 – 482 = MULTIPLICATION – Stage 1 and 2 Children must understand that multiplication is repeated addition 5x3 =5+5+5 0 5 10 15 Need to understand that: 3x5 is the same as 5x3 0 3 6 9 12 15 Stages 3 and 4 – Children continue to use number lines and arrays X 6 1 0 4 Grid method 23 x 8 = x 8 1 1 + 1 2 0 6 0 3 2 6 0 2 4 8 4 4 Short method 38 x 7 = 3 x 2 8 7 6 5 6 Grid method for TU X TU X 2 0 5 0 1 0 0 0 3 5 0 3 5 0 7 1 1 + 1 6 1 1 3 5 0 1 6 2 5 1 2 1 2 0 4 2 6 2 Stages 5 and 6 – Short method 56 x 27 = Children approximate first: 60 x 30 = 1800 5 6 X 2 7 3 9 2 56x7 1 1 2 0 56x20 1 5 1 2 1 Have a go!!! Use the grid method to calculate 43 x 6 Try the short method Calculate 56 x 43 using the grid method and short method DIVISION – Stage 1 and 2 – Children understand that division is repeated subtraction 4 groups of 3 in 12 12 3=4 0 1 2 3 4 5 6 7 8 9 10 11 12 13 Stage 3 – Children continue to use repeated addition on number lines including remainders 13 0 1 4=3r1 5 9 13 Stage 4 – Short division using chunking method 3 = 24 72 3) 72 - 30 42 - 30 12 - 6 6 6 0 10 x 10 x 2x 2x Answer = 24 Stages 5 and 6 – Children use larger multiples and numbers 864 24)864 - 720 144 - 72 72 - 72 0 24 = 36 30 x 3x 3x Answer = 36 Other Year 6 methods Please look at the leaflets/website. These are used if children are having difficulties with the chunking method Have a go!! Use a number line to demonstrate 14 7 = 2 Use the chunking method to work out 65 5 = 210 15 =