For many parents, the biggest challenge they face helping their child with high school math is that the material is too difficult for them to easily help out. Familiarize yourself with the range of ...

Everyone gets really wow'd when someone pulls off some exceptional mental math. The best part is, you can totally be that guy at the party with a little practice and preparation. What follows is 10 ...

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 ...

A number is divisible by 9 if the sum of its digits is greater than or equal to 9. 621 (6+2+1=9), for instance, is divisible by 9. Simply move the decimal point one place to the left to find the 10% ...