8. Multiplication of numbers close to each other (but not close to a power of 10)
Step 1: Consider the base as the nearest power of 10. For example, if the number is close to 80, we should take the base as 80 (8 ×10). Here the factor is 8. If the number is close to 50, we should take the base as 50 (5 ×10 or 100 ÷ 2). Here the factor can be 5 or 2.
Step 2: Apply the same rules as those of Nikhilam
Step 3: Multiply or divide by the factor obtained in step 1