To be able to do the problem 5(10 + 4) mentally, Zack does 50 + 20 instead of 5(14).

Question

Zack is using which of the following properties?

distributive
inverse
associative
commutative

Answer 1

Zack is using the distributive property.

The distributive property states that \( a(b + c) = ab + ac \). In this case, Zack sees \( 5(10 + 4) \) as \( 5 \times 10 + 5 \times 4 \), which equals \( 50 + 20 \). Thus, he is distributing the multiplication of 5 over the addition of 10 and 4.