Explain how you would use the commutative property of multiplication to answer 7×3

I don't see that you need to use that property here.  Simply multiply 3 by 7, obtaining 21, and be done with it.

7(3+x) is different and would require the Distributive Property of Mult.:

21 + 7x                 (Multiply each term inside parentheses by 7.)

1.3 and 1 1/3 are both closest to 1. hope this ; )