3 times 7 is 21. In symbols: 3 × 7 = 21, and 7 × 3 = 21 too.
3 × 7 means adding 3 to itself 7 times: 3 + 3 + 3 + 3 + 3 + 3 + 3 = 21.
3, 6, 9, 12, 15, 18, 21. The 7th multiple of 3 is 21.
3 × 7 = 3 × 3 + 3 × 4 = 9 + 12 = 21.
21 ÷ 3 = 7
21 ÷ 7 = 3
21 is odd. Prime factorization: 3 × 7.
| Multiplication | Answer |
|---|---|
| 2 × 7 | 14 |
| 4 × 7 | 28 |
| 3 × 6 | 18 |
| 3 × 8 | 24 |
| 3 × 9 | 27 |
| 3 × 5 | 15 |
| 5 × 7 | 35 |
See also: factors of 21.
Other numbers? Browse the multiplication table, the squares and cubes or the exponent calculator.