How_To_Be_Good_At_Math

CALCULATING • ADDING WITH A NUMBER GRID 81

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

61 62 63 64 65 66 67 68 69 70

91 92 93 94 95 96 97 98 99 100

81 82 83 84 85 86 87 88 89 90

71 72 73 74 75 76 77 78 79 80

51 52 53 54 55 56 57 58 59 60

Adding with a

number grid

To add numbers to 100, you can also use a number grid, or

100 square. This shows the numbers from 1 to 100 in rows of

10. You can do calculations by jumping from square to square.

To add 1, we just jump 1 square to the

right. When we get to the end of a row,

we move down to the next row and carry

on counting from left to right.

The addition starts with 56,

so let's mark it on the grid.

There are 2 groups of 10

in 26, so we need to jump

down 2 rows. This takes us to 76.

Now we add the 6 ones from

our 26 by jumping 6 squares

to the right. This takes us to 82.

So, 56 + 26 = 82

Let’s add 56 and 26 using

this number grid.

Look at this number grid. We can use it to

add numbers in two stages. To add 10,

we simply jump down to the next row,

because there are 10 numbers in each row.

56 + 26 =?

56 + 26 = 82

So, 20 + 50 = 70

Number grids are useful for

calculations with numbers to

100 which are tricky to work

out on a number line.

080_081_Adding_with_a_number_line_Adding_with_a_number_grid.indd 81 29/02/2016 18:02