Sumwise

What is 10 Percent of 42?

10% of 42 = 4.2

Result
4.2
Remaining
37.8
10% as decimal
0.1
42 + 10%
46.2

Sumwise · Data: exact arithmetic; unit definitions from NIST SP 811 · Updated · How we check it

How to work it out

  1. Turn the percentage into a decimal: 10 ÷ 100 = 0.1
  2. Multiply: 0.1 × 42 = 4.2
  3. Check: Work backwards: 4.2 ÷ 42 × 100 = 10%.

Another method. As a proportion of part to whole: 10/100 = part/42, so part = 10 × 42 ÷ 100 = 4.2. Both methods always give the same answer.

In a spreadsheet: =10%*42. Forgetting to divide the percentage by 100 makes the answer 100 times too big. Note that x% of y always equals y% of x.

What the result means

4.2 is the 10% share of 42. The remaining 90% is 37.8, and the two parts add back up to 42.

Discounts: 10% off an item priced $42 saves $4.2, so you pay $37.8.

Adding and taking away 10%

Increasing 42 by 10% gives 46.2 and decreasing it by 10% gives 37.8. These do not cancel out: raising 42 by 10% and then lowering the result by 10% ends at 41.58, because the second 10% is taken of a bigger number.

Related results

Results for nearby numbers
5% of 42

5% of 42 = 2.1

15% of 42

15% of 42 = 6.3

20% of 42

20% of 42 = 8.4

25% of 42

25% of 42 = 10.5

50% of 42

50% of 42 = 21

75% of 42

75% of 42 = 31.5

The other way round: 42% of 10

Practice

3% of 55
Show answer

3% of 55 = 1.65

45% of 48
Show answer

45% of 48 = 21.6

6% of 69
Show answer

6% of 69 = 4.14

8% of 68
Show answer

8% of 68 = 5.44

63% of 62
Show answer

63% of 62 = 39.06

17% of 48
Show answer

17% of 48 = 8.16

Calculate another

How answers are calculated and checked: methodology.

Questions

What is 10 Percent of 42?

10% of 42 is 4.2. Formula, steps and practice examples.

What is 10% off 42?

37.8. Taking 10% off leaves 90% of 42.

What is 42 plus 10%?

46.2. Adding 10% is the same as multiplying by 1.1.