Multiply number near to base

Eg.
 94*96


Taking base as 100
here 94 is 6 less than 100
96 is 4 less than 100


Step1:
write these value in right side of given number 

94        -6
96         -4

Step2:
 Multiply these value written in Rhs of given number

RHS
-6 x -4 = 24

Step 3:
Add either number diagonally

LHS
94 + (-4)90       OR          96 + (-6)= 90

Now write down LHS And RHS values together
 9024

Squaring two digit number above 50

LHS =    (25 + X)*100
RHS =     Sq(X)
where
X =  Number to be squares - 50
Sq =  Square of number
Answer can be found by adding LHS & RHS 


Take an example of squaring  54

Here
X = 54 - 50
    = 4
Therefore
 RHS =  Sq(X)
          = Sq(4)
          = 4*4
          =16

LHS = (25 + X)*100
         = (25 + 4)*100
         =2900


Answer is LHS +RHS = 2900+16= 2916

Squaring two digit number below 50

LHS =    (25-X)*100
RHS =     Sq(X)
where
X = 50 - Number to be squares
Sq =  Square of number


Answer can be found by adding LHS &  RHS 
Note:
This method can be applied to square number ranging from 26 to 49

Take an example of squaring 46

Here
X = 50  -  46
    = 4
Therefore
 RHS =  Sq(X)
          = Sq(4)
          = 4*4
          =16

LHS =( 25 - X)*100
         = (25 - 4)*100
         = 2100

Answer is 2116

Squaring two digit number ending with 5

Case 1:   unit place is 5
E.g. 15,45,95
Process

(45)2

we will find the answer in two steps i.e.  LHS and RHS 


Step1:

RHS : 
Square unit place number in our example
5x5 =25

Step 2:
LHS :
Add 1 to tens place number and Multiply with ten's unit number
(4+1)  x 4 
=5 x 4 
=20

Now write down LHS and RHS
So answer is  2025