Which property would allow you to use mental computation to simplify the problem 27 + 15 + 3 + 5?

Question

anonymous · Answer

wouldn't it be easier to do this in your mind if the 27 and 3 were next to each other, and if the 15 and 5 were together?

anonymous · Answer

Commutative and Associative Properties of Addition

aripotta · Answer

associative property of addition

anonymous · Answer

hmmm

anonymous · Answer

I think just commutative...

anonymous · Answer

$$27+15+3+5=27+3+5+15$$  by the commutative law

aripotta · Answer

well, you could use both

anonymous · Answer

associative would mean like "add (27 + 15) + (3 + 5)" or something... it is grouping them differently, but not changing the order.

anonymous · Answer

associative property is $(a+b)+c=a+(b+c)$ which allows you to write without parentheses, but there are no parentheses in the question

aripotta · Answer

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