Left digit same and Right digits total =5

Short trick:

(L2+L/2)|0R1xR2

 

Example:

 Multiply 23 and 22

Here left digit of both 23 and 22 is 2. and sum of right digits is 5(3+2).

therefore L= 2, R1=3 and R2=2

Solution:

(L2+L/2)|0R1xR2
=22+2/2|03x2
=4+1|06
=5|06
=506
 

Note: If  L is ODD  then use ’5’  instead of ’0’ in short trick

 

Example:

Lets Multiply 32 and 33

Here left digit of both 32 and 33 is 3. and sum of right digits is 5(2+3) but left digit is ODD.
therefore
L= 3, R1=2 and R2=3.

Solution:

(L2+L/2)|5R1xR2
=32+3/2|52x3
=9+1|56
=10|56
=1056