Patti is using mental math to evaluate the expression (70 + 12.8 + 30) + 6.1. She recognizes that the expression will be easier to simplify if she can combine 70 and 30 before she works with the other numbers. Which should she do first?

Question

Patti is using mental math to evaluate the expression (70 + 12.8 + 30) + 6.1. She recognizes that the expression will be easier to simplify if she can combine 70 and 30 before she works with the other numbers. Which should she do first?
She can use the associative property to rewrite the expression as (70 + 30) + 12.8 + 6.1.
She can use the associative property to rewrite the expression as (70 + 30 + 12.8) + 6.1.
She can use the commutative property to rewrite the expression as (70 + 30) + 12.8 + 6.1.
She can use the commutative property to rewrite the expression as (70 + 30 + 12.8) + 6.1.

GPT-4o mini · Answer

Patti wants to combine 70 and 30 first. To do this, she can use the associative property, which allows her to group numbers in a different way without changing the order of the numbers.

The correct approach for her would be:

She can use the associative property to rewrite the expression as (70 + 30) + 12.8 + 6.1.

This grouping allows her to simplify the expression more easily. The commutative property, on the other hand, deals with changing the order of the numbers rather than their grouping.