A percentage is a way of expressing a number as a part of 100. When you see the symbol %, it means you're looking at a percentage.

If you score 85% on a spelling test, you got 85 points out of every 100 points possible. If your phone battery is at 20%, that means 20 out of every 100 units of power remain. When a weather forecast says there's a 60% chance of rain, meteorologists mean that, in similar conditions, it would rain about 60 times out of 100.

Percentages make it easy to compare different amounts. Imagine one student answered 17 out of 20 questions correctly, while another got 42 out of 50 right. Which score is better? Converting to percentages (85% and 84%) makes the comparison instant and clear.

You'll see percentages everywhere: discount signs at stores (“30% off!”), sports statistics (a basketball player's free-throw percentage), or poll results showing what fraction of people prefer pizza over tacos. Scientists use percentages to show how much of something exists in a mixture. Percentages turn complicated fractions into numbers anyone can quickly understand and compare.