Square numbers, 1 to 20
| 1 × 1 = 1 | 2 × 2 = 4 | 3 × 3 = 9 | 4 × 4 = 16 |
| 5 × 5 = 25 | 6 × 6 = 36 | 7 × 7 = 49 | 8 × 8 = 64 |
| 9 × 9 = 81 | 10 × 10 = 100 | 11 × 11 = 121 | 12 × 12 = 144 |
| 13 × 13 = 169 | 14 × 14 = 196 | 15 × 15 = 225 | 16 × 16 = 256 |
| 17 × 17 = 289 | 18 × 18 = 324 | 19 × 19 = 361 | 20 × 20 = 400 |
Square numbers sit on the diagonal of the multiplication chart. What do you add to get from one to the next?
Free from fieldbooklearning.com/charts/