It’s easy to tell if a given whole number is divisible by 2. Just check whether the last digit is even. There are also simple rules to determine whether a number is ...

This article is a modified and updated version of one I wrote in—oddly enough—2008 and then updated for 2012. Barring a colossal asteroid impact or a Trump presidency, I’ll probably be around to do it ...

Learn how to check divisibility by 13 with Sall's Theorem! This easy-to-follow method helps you determine if a number is divisible by 13 without doing long division. Perfect for math enthusiasts and ...

Examples: (1) 475 is divisible by 25 but not by 125. (2) 465 is divisible by 5 but not by a higher power of 5. As 4 + 6 + 5 = 15, it is divisible by 3 though. (3) To check for divisibility of ...

You probably haven’t had to do longhand math in years, but you do mental math every day. Or maybe you google math problems ten times a day, because you’ve forgotten how to do any math beyond your ...

This is a preview. Log in through your library . Journal Information The Mathematics Teacher (MT), an official journal of the National Council of Teachers of Mathematics, is devoted to improving ...