Mental Squaring using (a - b)^2 approach

In this (a - b)² approach to mental number squaring, the concept is to split the original number to one having 10's. It is similar to the ( a + b)² approach but differs in the expanded expression.

Principle: (a - b)² = a² - 2ab + b²

Example: 34²

Step 1: Split 34 into 40 - 6
Step 2: Replace 34² by (40 - 6)²
Step 3: Expand Step 2. 40² - 2(40)(6) + 6²

Mentally it is easy to do 40² = 1600.
Mentally it is also simple to do 6² = 36.

Adding the above 2 results mentally is also easy, 1600 + 36 = 1636, with the "00" aiding the process.

Next, we need to perform the centre term "2ab" ==> 2(40)(6) = 480

Subtracting this last maths operation result of 480 from the 1636 gives 1156 (ANSWER).

The last operation of subtracting is the obstacle in speed compared to the other approaches in Mental Number Squaring.

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