Subtraction
Children can subtract using practical methods (pasta or buttons are great for addition) or can use number lines. They can also use a hundred square or make one of their own:
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 |
| 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 |
| 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 |
| 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 |
| 41 | 42 | 43 | 44 | 45 | 46 | 47 | 48 | 49 | 50 |
| 51 | 52 | 53 | 54 | 55 | 56 | 57 | 58 | 59 | 60 |
| 61 | 62 | 63 | 64 | 65 | 66 | 67 | 68 | 69 | 70 |
| 71 | 72 | 73 | 74 | 75 | 76 | 77 | 78 | 79 | 80 |
| 81 | 82 | 83 | 84 | 85 | 86 | 87 | 88 | 89 | 90 |
| 91 | 92 | 93 | 94 | 95 | 96 | 97 | 98 | 99 | 100 |
and also try holding the largest number in their head and counting back.
20 - 7 =
15 - 9 =
12 - 6 =
18 - 8 =
10 - 3 =
20 - 14 =
17 - 3 =
12 - 10 =
10 - 9 =
19 - 11 =
In a box there are 15 sweets. Jeff eats 6 of them. How many are left?
Jane has 20p. She spends 12p. How much change does she get?
Challenge:
In a box of 10 colouring pencils, 3 are blue and the rest are green. How many are green?