Example  1 : 85*85 = 7225

Step 1 : Last 2 digits of the result will always be = 25

Step 2 : First 2 digits will be 8*9 = 72 (i.e. multiply the first digit with immediate higher number )

Step 3 : 7225 (It’s the final answer)

 

Please try : 

55 * 55

35 * 35