Squaring of 3 digit numbers ending in 5

Let me explain the easier method for squaring 3 digit numbers ending in 5 with an example:

Example : 345 ²

Step 1 : square the last digit 5 and put it in the last places of the result

 
       ****25

Step 2 : take the just previous digit i.e 4, multiply 4 with (4+1) ie 4 x 5 = 20 put zero in the result and carry forward 2

      
       ***025

step 3 : multiply the first two digits of the number to be squared and double it i.e
      
      3 x 4  = 12 ; 12 x 2 = 24
       
       Now add the 100^th position digit number of the number to be squared and carry forward to the result
      
       24 + 3 + 2 = 29
      
       Put 9 in the result and carry forward 2
    
       **9025

Step 4 : Square the 100^th position digit and add carry forward and put it to the result

 here 3 ² = 9; 9 + 2 = 11

        119025

 345 ² = 119025   

Example 2 : 685 ²

Step 1 : square 5 and put it in the last places of the result
 
       ****25

Step 2 : multiply 8 with (8+1) ie 8 x 9 = 72 put 2 in the result and carry forward 7      

       ***225

step 3 : multiply the first two digits of the number to be squared and double it i.e
      

      6 x 8  = 48 ; 48 x 2 = 96

       
       Now add the 100^th position digit number of the number to be squared and carry forward to the result
      

       96 + 6 + 7 = 109

      

       Put 9 in the result and carry forward 10

    

       **9225

Step 4 : Square the 100^th position digit and add carry forward and put it to the result

 here 6 ² = 36; 36 + 10 = 46

        469225

 685 ² = 469225