Add and Subtract Within 20

In this worksheet, we will practice adding and subtracting using fact families and backwards reasoning.
Part 1: fact families example: 7 + 5 = 12, so 12 - 7 = 5
Part 2: backwards reasoning example: 8 + 4 + 2 = 8 + 6 = 14
(Keep in mind that both equations have to equal the number at the end)