CALCULATING • THE GRID METHOD 113So, 37 × 18 = 666Finally, we simply add up all the numbers
in the grid row by row and write the total
at the end of each row. We get 370 and 296.
Then we can add these numbers together
using column addition to find the total:
370 + 296 = 666Next, multiply the number at the top of
each column by the number at the start
of each row, and write the product in each
box in the grid.Quicker grid methods
When we get more confident with multiplication calculations, we can use quicker
forms of the grid method. They are like the one we have just used, but have fewer
steps and a simpler grid. Here are two shorter grid methods to work out 37 × 18.If we partition the numbers in a
calculation into fewer, larger chunks,
we don't have to do so many calculations.Once we understand what we are doing,
we can draw a quick and simple grid
instead of a box.300
100
100
80
80
100
100
80
80
100
100
80
80
70
70
56
56
240 56
70
× 30 7
10 300 70
8 240 56
30 7
10
8
Multiply the number at the top
of the column by the number
at the start of the rowDraw a
simpler grid
Partition the numbers
into fewer chunksFind the total
of each row37 × 18 = 666
37
10 10 10 710
8
18
37
10 10 10 710
8
18
Use column addition to add
the two numbers together++++++370
296
666
1==370
296
666
1==370
296
666
1==112_113_The_grid_method.indd 113 29/02/2016 14:11