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The method traditionally used for multiplying two numbers of two or more digits is
long multiplication, but this is quite an abstract process which is difficult to understand for many children.
Grid Multiplication (also known as the
Grid Method) is now taught in schools as an intermediate stage before long multiplication.
With
grid multiplication, the two numbers to be multiplied are split (
partitioned) up into their tens and units components - e.g. 34 = 30 + 4, or hundreds, tens, and units components - e.g. 345 = 300 + 40 + 5. (Click here for our
2-digit number partitioning worksheets and
3-digit number partitioning worksheets for partitioning practice)
The
grid method enables a complex multiplication to be broken up into a collection of relatively simple multiplications followed by some
column addition.
Grid Method Example
54 x 12 can be
partitioned to give us (50 + 4) x (10 + 2)
this can be expanded to four simple multiplications which when added together give the final answer: (50 x 10) + (50 x 2) + (10 x 4) + (4 x 2).
This is done with the use of a
grid as shown below:
x | 10 | 2 |
50 | 500 | 100 |
4 | 40 | 8 |
total | 540 | 108 |
Total up the columns and write the totals in the row at the bottom of the grid. Then finally add together those totals for the final answer. Here 54 x 12 =
540 +
108 =
648.
The Grid Method
can be used to multiply very large numbers using a larger grid, but by the time a child is confident multiplying 3- and 4- digit numbers using grid multiplication, they are ready for long multiplication which is a faster method.
HTU x TU Grid Multiplication Worksheets
Here numbers of type HTU are multiplied by numbers of type TU using the grid method, for example
154x12,
391x74.
Next move on to
Grid Multiplication HTUxHTU.