Even in an age where everyone has a calculator application on their mobile phone it's a handy trick to be able to calculate in your head. Use these calculation shortcuts to crunch numbers with ease.
Photo by jekert qwapo.
Over at the Wired How-To Wiki they've started a list of shortcuts and tricks for calculating larger numbers quickly. While some of them are interesting for the sake of dazzling your friends with your CPU-like brain, others are more practical like:
Fives Times: If you have a multiplication of five, then an easy way to find the answer is to half the multiplied number and times by ten.
For example: 24 * 5 = (24 / 2) * 10 = 120
For more shortcuts check out the wiki at the link below. Know a calculation shortcut or two of your own? Let's hear about it in the comments.
Do Speedy Math in Your Head [Wired]