Now, in the multiplications we have just discussed, the factors in any one multiplication have all been different numbers. In the multiplication for example, we used 3 as a factor once, and 4 as a factor once. In the multiplication we used 2 as a factor once, 3 once, and 5 once.

But we can have multiplications in which we use the same number (same quantity, that is) as a factor more than once, can’t we? For example, in we use 2 as a factor twice.