Hi folks! In this post we are going to learn the multiplication of two digit numbers near by hundred in 3-5 seconds

 Example 97x94?




from the figure  you can easily understand  that
1) 97 is 3less than 100
2)94 is 6 less than 100
3) in the result first two digits can be found from 97-6 or 94-3 =91
4)last digits obtained from 3 x 6=18
result obtained in 5 secs   try yourself.........

if the numbers given are above 100

Example 104 x106?

the figure explains very well  
1)104 is 4 more than 100
2)106 is 6 more than 100
3)In the result first two digits can be found from 104+6 =106+4 =110
4)last digits obtained from 4 x 6=24we can use easily up to 120 if we know up to 20 tables perfectly

let's see one more example ....
Example 112 x110?

Here,
we have product of last digits 12 x10 =120 is a three digit number
So digit 1 to be added to 122 as shown in the figure....

By applying the same technique we can find squares of number from 85 to 120
By simple single line  i will present the way
note: we are taking 100 as base here(91²) = (91-9)x 100+ (9²) =8200+1 =8281
(92²) = (92-8)x 100+ (8x8) =8400+64 =8464
(93²)= (93-7)x 100+ (7x7) =8600+49 =8649

Here, we have a simple explanation..
1) 91 is 9 less than 100 so the number to be added to get last digits is 9²      
2) multiplying by 100 for understanding sake only if your thorough  directly you can write as (91-9)(9²)= 8281
 
try the remaining  up to 120
in the next post we are going to learn cubes and finding of cuberoots in fast way