Prerequisites: Counting

Addition of whole numbers can be done pretty much by just counting.

For example: 4 + 1 = 5, the same as counting to the next number, but 4 + 2 = 6, you count twice. Technically, you are expanding 4 + 2 = 6 to 4 + 1 + 1 = 6.

• ${\displaystyle 36+11=47}$, then, ${\displaystyle 47-36=11}$, ${\displaystyle 47-11=36}$