To use the multiplication grid, partition the numbers being multiplied into 10s and units to create easier numbers to multiply, and then add the results of the smaller multiplications together to get the final result. For example, if multiplying 27 by 4, split 27 into 20 and 7, multiply both numbers by 4, and add the answers to get the final result.
When multiplying a two-digit number by another two-digit number, both must be partitioned and placed into the grid. Multiply the numbers linked to each box together, and add all of the answers together to find the result of the multiplication.
Fractions and decimals can also be multiplied using the multiplication grid. If multiplying a number by 1 1/2 or 1.5, make a partition by separating the 1 from the 1/2 or 0.5. It is also possible to perform algebraic multiplications using this method.
Multiplication grids break down difficult multiplication into more manageable numbers. The method is useful in solving large multiplications without a calculator. The grid method is often taught to schoolchildren, and while it is more time-consuming than long multiplication due to the additional steps, the method generally is simpler to follow. The distributive law applies to multiplication grids.