We know that it is easy to find squares of 10, 20, 30, etc. So if we know how far is the number from 10s – we can use the below steps to find squares. We will take two examples 43 and 67

First example:

First example:

**Find Square of 43****STEP 1:**Find difference between the number and closest 10s.

*In this case, ten closest to 43 is 40. So, 43 - 40 = 3*

**STEP2:**Calculate square of this difference.

*3^2 = 9*

**STEP3:**Calculate twice of “product of difference and ten we selected”

*2*3*40 = 240*

**STEP 4:**Add output of step2 and step 3 to square of closest ten that we selected

*1600 + 240 + 9 =*

**1849**Second example:

**Find Square of 67**

**STEP 1:**Find difference between the number and closest 10s.

*In this case, ten closest to 67 is 70. So, 67 - 70 = -3*

**STEP2:**Calculate square of this difference.

*(-3)^2 = 9*

**STEP3:**Calculate twice of “product of difference and ten we selected”

*2*(-3)*70 = -420*

**STEP 4:**Add output of step2 and step 3 to square of closest ten that we selected

*4900 - 420 + 9 =*

**44****89****Logic behind this rule:**

(A + B)^2 = A^2 + B^2 + 2AB