Two Worksheets, with Answer Keys, on the Associative Property of Addition

Here are two worksheets on the associative property of multiplication with their answer keys attached. When you click to download, you should have a single, four-page-long document. Any problems, please advise.

If you find typos in these documents, I would appreciate a notification. And, as always, if you find this material useful in your practice, I would be grateful to hear what you think of it. I seek your peer review.