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 ...

Calculating profit as a percentage of revenue shows relative profitability, like Apple's 30.5% vs Fitbit's 20.5%. Common size income statements allow comparisons across companies and time by ...

This post explains how to calculate Weighted Average in Excel with percentages. In a standard arithmetic average where the sum of values is divided by the number of values, each data value is treated ...

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 ...