The calculator on your Apple devices can do more than add, subtract, multiply and divide. Here's how it can help you with all kinds of math problems.

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 ...

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

Estimate how much your money can grow with our free investment return calculator. Enter your planned contributions, timeline, rate of return and compounding frequency to get started. Many, or all, of ...

Disposable batteries seem so 1990s. Sure, it’s nice to be able to spend a couple of bucks at the drugstore and get a flashlight or TV remote back in the game, but when the device is a daily ...

Jason Fernando is a professional investor and writer who enjoys tackling and communicating complex business and financial problems. David Kindness is a Certified Public Accountant (CPA) and an expert ...