Everyday math, explained

A little clearer.

Short guides to the numbers you run into in real life.

A little math, a lot clearer

Good to know.

20% off, then 10% off. So why isn’t it 30%?

A simple way to understand stacked discounts and find the price you actually pay.

Read the guide Everyday percentages

Percent or percentage points? There’s a difference.

The same change can have two correct numbers. Here’s how to tell them apart.