#### Answer

36

#### Work Step by Step

The Commutative Property of Addition states that order of addition does not matter, so we add all three numbers in any order we choose.
21+6=27
27+9=36

Published by
Prentice Hall

ISBN 10:
0133281140

ISBN 13:
978-0-13328-114-9

36

You can help us out by revising, improving and updating this answer.

Update this answerAfter you claim an answer you’ll have **24 hours** to send in a draft. An editor
will review the submission and either publish your submission or provide feedback.