How to find 10 percent of 400
"Percent" means per hundred, so 10% is the fraction 10/100, or 0.1 as a decimal. Taking 10 percent of 400 means multiplying 400 by that fraction:
10% of 400 = 400 x 10 / 100
= 4,000 / 100
= 40The same answer comes from the decimal form: 400 x 0.1 = 40. And because multiplication is commutative, 10% of 400 equals 400% of 10, which is sometimes the easier way to see it in your head.
Mental math shortcut
10% of 400 is 40 (move the decimal one place left), and 1% is 4. Build 10% from those pieces: 1 x 40 = 40.
Nearby percentages of 400
| Percent | Of 400 | 400 minus it | 400 plus it |
|---|---|---|---|
| 1% | 4 | 396 | 404 |
| 5% | 20 | 380 | 420 |
| 9% | 36 | 364 | 436 |
| 11% | 44 | 356 | 444 |
| 15% | 60 | 340 | 460 |
| 20% | 80 | 320 | 480 |
| 25% | 100 | 300 | 500 |
| 30% | 120 | 280 | 520 |
| 50% | 200 | 200 | 600 |
| 75% | 300 | 100 | 700 |
10 percent of other amounts
| Amount | 10% of it |
|---|---|
| 80 | 8 |
| 100 | 10 |
| 120 | 12 |
| 150 | 15 |
| 200 | 20 |
| 250 | 25 |
| 300 | 30 |
| 500 | 50 |
| 600 | 60 |
| 750 | 75 |
Where this comes up
A 10% discount on a 400 price takes off 40, leaving 360. A 10% tip or tax on 400 adds 40, for a total of 440. If 400 is a score out of a possible total, 10% of it is the share 40 represents. For percent change, reverse percentages, and "X is what percent of Y", use the full percentage calculator.