Last digit of number | last digit of square |
0 | |
1 | |
4 | |
9 | |
6 | |
5 | |
6 | |
9 | |
4 | |
1 |
last digit of a2 ends with and | last digit of b2 ends with then | last digit of c2 must end with |
1+ | 0= | 1 |
1+ | 1= | 2 Not admissable c2 cannot end with 2 |
1+ | 4= | 5 |
1+ | 5= | 6 |
1+ | 6= | 7 X |
1+ | 9= | 0 |
4+ | 0= | 4 |
4+ | 4= | 8 X |
4+ | 5= | 9 |
4+ | 6= | 0 |
4+ | 9= | 3 X |
6+ | 0= | 6 |
6+ | 4= | 0 |
6+ | 5= | 1 |
6+ | 6= | 2 X |
6+ | 9= | 5 |