21 times 30 is 630. In symbols: 21 × 30 = 630, and 30 × 21 = 630 too.
21 × 30 means adding 21 to itself 30 times: that is 30 copies of 21, which add up to 630.
21, 42, 63, 84, 105, 126, 147, 168, 189, 210, 231, 252, ... (keep going to the 30th multiple). The 30th multiple of 21 is 630.
21 × 30 = 21 × 30 = 630 = 630.
Halve one number and double the other: 21 × 30 = 15 × 42 = 630.
630 ÷ 21 = 30
630 ÷ 30 = 21
630 is even. Prime factorization: 2 × 3 × 3 × 5 × 7.
| Multiplication | Answer |
|---|---|
| 20 × 30 | 600 |
| 22 × 30 | 660 |
| 21 × 29 | 609 |
| 21 × 28 | 588 |
| 23 × 30 | 690 |
| 19 × 30 | 570 |
Other numbers? Browse the multiplication table, the squares and cubes or the exponent calculator.