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?

Answer 1

GIVEN :

Patti is using mental math to evaluate the expression (70 + 12.8 + 30) + 6.1

TO FIND :

The properties of operations allow Patti to simplify.

SOLUTION :

Given that Patti is using mental math to evaluate the expression (70 + 12.8 + 30) + 6.1.

Option d) She can use the commutative property to rewrite the expression as (70 + 30 + 12.8) + 6.1 is correct.

For :

Patti's expression is (70 + 12.8 + 30) + 6.1

By using the commutative property of addition

a+b=b+a

(70 + 12.8 + 30) + 6.1

= (70+30+12.8)+6.1 (here a=12.8 and b=30)

∴ the properties of operations allow Patti to take is the commutative property of addition.