21 divided by 2 is 10 with a remainder of 1, or 10.5 as a decimal. In symbols: 21 ÷ 2 = 10.5.
| Form | Answer |
|---|---|
| Quotient and remainder | 10 remainder 1 |
| Decimal | 10.5 |
| Fraction | 21/2 |
| Mixed number | 10 1/2 |
| Percent | 1050% |
Ask how many times 2 fits into 21. 2 × 10 = 20, and 2 × 11 = 22 is too big, so 2 goes into 21 exactly 10 times with 21 − 20 = 1 left over.
The remainder 1 is 1/2 of another 2, and 1 ÷ 2 = 0.5. So 21 ÷ 2 = 10 + 0.5 = 10.5.
Multiply back: 10 × 2 + 1 = 20 + 1 = 21. ✓
| Division | Answer |
|---|---|
| 20 ÷ 2 | 10 |
| 22 ÷ 2 | 11 |
| 21 ÷ 3 | 7 |
| 19 ÷ 2 | 9 R 1 |
| 23 ÷ 2 | 11 R 1 |
| 42 ÷ 2 | 21 |
| 21 ÷ 4 | 5 R 1 |
See also: factors of 21.
Other numbers? Browse all division answers, the multiplication table or the fraction calculator.