Tabla del -21
| -21 | X | 1 | = | -21 |
| -21 | X | 2 | = | -42 |
| -21 | X | 3 | = | -63 |
| -21 | X | 4 | = | -84 |
| -21 | X | 5 | = | -105 |
| -21 | X | 6 | = | -126 |
| -21 | X | 7 | = | -147 |
| -21 | X | 8 | = | -168 |
| -21 | X | 9 | = | -189 |
| -21 | X | 10 | = | -210 |
| -21 | X | 1 | = | -21 |
| -21 | X | 2 | = | -42 |
| -21 | X | 3 | = | -63 |
| -21 | X | 4 | = | -84 |
| -21 | X | 5 | = | -105 |
| -21 | X | 6 | = | -126 |
| -21 | X | 7 | = | -147 |
| -21 | X | 8 | = | -168 |
| -21 | X | 9 | = | -189 |
| -21 | X | 10 | = | -210 |