Square of any 2 digit number

Let me explain this trick by taking examples

67^2 = [6^2][7^2]+20*6*7

      

= 3649+840 

         

 = 4489

similarly

25^2  =  [2^2][5^2]+20*2*5 

          

= 425+200 

= 625

Take one more example

97^2 = [9^2][7^2]+20*9*7 

= 8149+1260

= 9409

Here [ ] is not an operation, it is only a separation between initial 2 and last 2 digits