Scientific American presents Math Dude by Quick & Dirty Tips. Scientific American and Quick & Dirty Tips are both Macmillan companies. Long time math fans may remember our first foray into the world ...

Percentages are a way of expressing proportion. Proportion tells you how much of one thing there is in relation to the whole. 'Per cent' means ‘out of 100’ and a percentage is written as a number with ...

If you are using Microsoft Excel to manage numerical data, at some point you're inevitably going to display percentages. Doing so can give you a new insight, or make summarizing heaps of data a bit ...

How to calculate percentages is easier than you think. Quick, what’s 36% of 25? Or how about 250% of 20? Learn a quick and dirty tip to help you calculate all of those pesky percentages in your head.