In TODAY.com's Expert Tip of the Day, a trainer shares an efficient strength training move for when you're short on time.

This Olympiad-style exponential problem looks simple at first — until you try solving it. Test your skills and see if you can crack it before I walk through the clever solution step-by-step.

Math scores in the U.S. have been so bad for so long that teachers could be forgiven for trying anything to improve them. Unfortunately, many of the strategies they’re using ...