Mentally Square of any number ending with 5.

• Step 1) In case of (75)^2, We simply multiply the 7 by the next number up,8. This gives us 56 as the first of the ans.
• Step 2) Remember that, as number ending with 5 last two digits of our answer is 25.
• Our last answer must be 25, This is common for every number ending with 5.

Examples,
      1) (75)^2
      Step 1) :- 7 * 8 = 56
      Step 2) :-  Place 25 next to the result from step first.
                  = 5625

So we get, (75)^2 = 5625.

      2) (95)^2
      Step 1) :- 9 * 10 = 90
      Step 2) :-  Place 25 next to the result from step first.
                  = 9025

So we get, (95)^2 = 9025.

     3) (65)^2
      Step 1) :- 6 * 7 = 42
      Step 2) :-  Place 25 next to the result from step first.
                  = 4225

So we get, (65)^2 = 4225.

     4) (115)^2
      Step 1) :- 11* 12 = 132
      Step 2) :-  Place 25 next to the result from step first.
                  = 13225

So we get, (115)^2 = 13225.

😊Best Luck 👍