Addition technique

1.   How to additions fast. For example we have to do a simple addition like 234 + 563+ 985 + 349.  
Sol. Traditional Method:

Alternative Method 1:

Instead of doing like this we first add all the digits in the hundred's place.  2 + 5 + 9 + 3 = 19. Put 2 zero's to the right hand side so we get 1900.
Now add the digits in the tenth's place. 3 + 6 + 8 + 4 = 21. Put 1 zero to the right hand side so we get 210.
Now add the digits in the units place 4 + 3 + 5 + 9 = 21.
Now 1900 + 210 + 21 = 2131

Alternative Method  2:
First add all the hundreds to the first number. So we get 234 + 500 + 900 + 300 = 1934.  Now add the tens to this number 1934 + 60 + 80 + 40 = 1934 + 180 = 1934 + (200 - 20 ) = 2134 - 20 = 2114.
Now add the unit digits to this number = 2114 + 3 + 5 + 9 = 2014 + 17 = 2114 + ( 20 - 3 ) = 2134 - 3 - 2131.
If you do adequate practice you can easily add numbers without much effort. Only thing required is practice.