when multiplying negatives, i find the following equivalent expressions of a series of addition a more direct explanation since multiplication is just a repeated addition.

what do mathematicians call the addition progressions from #4 to #1?

on -1:

1. -1 * -3 =-1 + 1 + 1 + 1 + 1= 3

2. -1 * -2 =-1 + 1 + 1 + 1= 2

3. -1 * -1 =-1 + 1 + 1= 1

4. -1 * 0 =-1 + 1= 0

5. -1 * 1 =-1 + 0= -1

6. -1 * 2 =-1 + -1= -2