Every so often its good to exercise your brain with a math problem or two that forces you to recall principles you learned decades prior. Can you solve 5+5x5+5 without a hitch?

Your iPhone's calculator is a powerful tool at your fingertips just waiting to do math quickly and easily. Here are some tricks you need to know about.

Posts from this topic will be added to your daily email digest and your homepage feed. Math Notes has some quirks, but I already love being able to do basic math inside just about any text box. Math ...