Square of a two-digit number:
Quick Method:
(82)2= 6404
32 [8*2*2] ==> 8 and 2 from original number itself and another 2 from the power of 82 i.e. 2
6724
Likewise for square of 79:
(79)2= 4981
126 [7*9*2]
6241 ==> Final Answer
Likewise for square of 63:
(63)2
= 3609
+ 36
= 3969 ==>Final Answer