Short cut to get product of two consecutive odd or even
numbers
If you are doing product of two consecutive odd or even
numbers, simply square the middle number
and the subtract one form it.
Logic : If (n+1)
and (n-1) are two consecutive odd or even numbers then their product is (n+1)(n-1) = n2-1
Examples
11 x 13 = 122
– 1 = 143
14 x 16 = 152
– 1 = 224
44 x 46 = 452
– 1 = 2024
24 x 26 = 252
– 1 = 624