Answer:
Explanation:
I'm not sure my way is going to be any quicker or better. Let's take an example.
Suppose you start with 456
Put a decimal at the end of the 6. You get 456.
Shift the decimal to the left one place 45.6
Divide by 2
22.8 (done mentally)
Note: dividing by 2 is easier than dividing by 5. Or multiplying by 5 for that matter.
Check the result.
456 * 5/100 =2280 / 100.
Shift a decimal 2 places to the left.
22.80 which agrees with your result.