Use the sales tax calculator to figure out how much sales tax you’ll potentially owe on a purchase. Many, or all, of the products featured on this page are from our advertising partners who compensate ...

The Rule of 72 is a simple calculation tool for investors to use, but it's not necessarily the most accurate. Here are some ...

In January I wrote a piece titled “ 5 Physics Equations Everyone Should Know .” Lots of you weighed in with your own ...

NPR's Ailsa Chang speaks to mathematician Eugenia Cheng about the Pascaline -- a 17th-century invention credited as the first mechanical calculator.

In grade school, you were constantly drilled on mathematics. But as an adult, those lessons all too often fall to the wayside. See if you can remember elementary formulas with this math problem.