How to find 40 percent of 10
"Percent" means per hundred, so 40% is the fraction 40/100, or 0.4 as a decimal. Taking 40 percent of 10 means multiplying 10 by that fraction:
40% of 10 = 10 x 40 / 100
= 400 / 100
= 4The same answer comes from the decimal form: 10 x 0.4 = 4. And because multiplication is commutative, 40% of 10 equals 10% of 40, which is sometimes the easier way to see it in your head.
Mental math shortcut
10% of 10 is 1 (move the decimal one place left), and 1% is 0.1. Build 40% from those pieces: 4 x 1 = 4.
Nearby percentages of 10
| Percent | Of 10 | 10 minus it | 10 plus it |
|---|---|---|---|
| 1% | 0.1 | 9.9 | 10.1 |
| 5% | 0.5 | 9.5 | 10.5 |
| 10% | 1 | 9 | 11 |
| 15% | 1.5 | 8.5 | 11.5 |
| 20% | 2 | 8 | 12 |
| 25% | 2.5 | 7.5 | 12.5 |
| 30% | 3 | 7 | 13 |
| 35% | 3.5 | 6.5 | 13.5 |
| 39% | 3.9 | 6.1 | 13.9 |
| 41% | 4.1 | 5.9 | 14.1 |
| 45% | 4.5 | 5.5 | 14.5 |
| 50% | 5 | 5 | 15 |
40 percent of other amounts
| Amount | 40% of it |
|---|---|
| 20 | 8 |
| 25 | 10 |
| 30 | 12 |
| 40 | 16 |
| 50 | 20 |
Where this comes up
A 40% discount on a 10 price takes off 4, leaving 6. A 40% tip or tax on 10 adds 4, for a total of 14. If 10 is a score out of a possible total, 40% of it is the share 4 represents. For percent change, reverse percentages, and "X is what percent of Y", use the full percentage calculator.