The answer is 10. Below: three ways to calculate it, a mental shortcut, and the real-world contexts where this percentage shows up.
10% of 100 is 10.
A foundational example: 10% of any number is that number with the decimal moved one place left.
Divide the percent by 100 to convert it: 10 ÷ 100 = 0.1.
Multiply: 100 × 0.1 = 10.
10% means 10/100. So 10% of 100 is (10 × 100) ÷ 100.
Compute: 10 × 100 = 1000, then divide: 1000 ÷ 100 = 10.
For 10% of anything, move the decimal point one place to the left. So 10% of 100 is 10. This is the foundation for almost every other mental percentage shortcut.
10% is the most useful percentage in mental math because it requires no calculation at all — just shift the decimal point one place to the left.
10% of 100 is 10. Verify: write 100 as 100.0, move the decimal one place left to get 10.0. That is the answer for 10% of any number.
If you only needed to look up this one number, here are some related ones using the same base of 100:
| Calculation | Answer |
|---|---|
| 5% of 100 | 5 |
| 15% of 100 | 15 |
| 20% of 100 | 20 |
| 25% of 100 | 25 |
| Calculation | Answer |
|---|---|
| 10% of 5 | 0.5 |
| 10% of 10 | 1 |
| 10% of 15 | 1.5 |
| 10% of 20 | 2 |
| 10% of 25 | 2.5 |
For any percentage of any number, use our percentage of a number calculator.
Multiply 100 by 0.1 (the decimal form of 10%). Or equivalently, multiply by 10/100. The result is 10.
Divide 10 by 100 and multiply by 100. That is exactly 10% — confirming the original calculation.