MULTIPLICATION OF NUMBERS CLOSE TO 100

EX :1) 98x97
98 is 2 less than 100& 97 is 3 less than 100.
now multiply 2&3
write 2x3=06
and then take 98-3 or 97-2 which is equal to 95
therefore ans is 9506.

98.............2
x 97...............3
-----------------
95 06
here 95= 98-3 or 97-2 (cross subtraction)
06=2x3

so 98x97=9506

ANOTHER EXAMPLE: 108X109
Here 108 is 8 more than 100&109 is 9 more than100
now multiply 8&9
and write it as 72
now take 108+9 or109+8.which is =117
THEREFORE 108x109=11772

108.........8
x 109..........9
.....................................
117 72

here 117=108+9 or 109+8
72=8x9

THEREFORE 108X109= 11772