Question

Marcela's grocery bills for three months were

$75, $87, and $25. To add the bills mentally,
Marcela thought:
"75 + 87 + 25 = 75 + 25 + 87"
What property did Marcela use?

Answer 1

Marcela used the Associative Property of Addition.

Explanation:

The Associative Property of Addition states that when adding three or more numbers, the grouping of the addends does not change the sum. In other words, no matter how the addends are grouped, the sum remains the same. More specifically:

For any three numbers a, b, and c, (a + b) + c = a + (b + c)

For example: (2 + 3) + 4 = 2 + (3 + 4) = 9

So, if Marcela used the Associative Property of Addition to add her grocery bills, she grouped the addends in a different order, but still arrived at the same sum.

Answer 2

Marcela used the commutative property of addition. This property states that the order of numbers being added does not affect the sum. In this case, Marcela rearranged the order of the numbers being added (75, 87, and 25) without changing the final result.