What Is The Breaking Apart To Find Each Product 3x7=?

This one could be done at least a couple of ways.
3*7 = (2+1)*7 = 14+7 = 21

3*7 = 3*(5+2) = 15+6 = 21

How you break it depends on which math facts you are most comfortable using.

(4+3)3
4x3=12
3x3=9
9+12= 21