Integer Multiplication 2 (A)

Step 5 -
From Step 1 to 4, +3 has been multiplied by numbers which are reducing at each step by 1. Hence the product has also been reducing by 3 at each step.

Extending the same idea, when 0 is reduced by 1 to -1, logically the product 0 should reduce by 3 to -3. The same logic is followed in all the ste