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 ...

Let's face it: Even the best budgets can't always predict your actual expenses. Things happen. Unexpected costs arise. That's life. That's why it's so useful to review your budget after a project is ...

Have you ever stared at a spreadsheet, struggling to make sense of percentage calculations that just don’t seem to add up? Whether it’s a confusing formula, a misstep with zero values, or an ...

Investopedia contributors come from a range of backgrounds, and over 25 years there have been thousands of expert writers and editors who have contributed. Robert Kelly is managing director of XTS ...

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.

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 ...

A retail business buys finished goods from suppliers and manufacturers and sells them to consumers and businesses. Retailers may also assemble or manufacture products for resale. Financial ratios ...

One way to find a percentage of an amount is to use 1%, 10% and 50% as building blocks. 1%, 10% and 50% can be used as building blocks for working out percentages in your head. 1% is 1⁄100. Work out 1 ...