7172
Taking square root of 7172, we find that 116 has been left
We see that 7172 is greater than (84)2
| | 84 |
| 8 | 71 7264 |
| 164 | 772656 |
| | 116 |
On adding the required number to 7172, we get (85)2 i.e., 7225
Required number = 7225 - 7172 = 53