The commutative property applies to addition and multiplication and it means that if you take two numbers and add or multiply them it doesn't matter which order the numbers come in, so, for example, 2 times 3 is the same as 3 times 2. In multiplication tables or charts this is useful because you can cut the size of the table or chart down. If it goes up to 12 times 12 in the rows and columns, you only need one cell or box for products. For example, the box for 6*9=54. You don't need another box for 9*6. The table or chart looks like a big triangle with numbers in.