Finding 15 percent of a number
Choose a 2-digit number.
Multiply the number by 3.
Divide by 2.
Move the decimal point one place to the left.
Example:
If the number selected is 43:
Multiply by 3: 3 × 43 = 129
Divide by 2: 129/2 = 64.5
Move the decimal point one place to the left: 6.45
So 15% of 43 = 6.45.
See the pattern?
If the number selected is 72:
Multiply by 3: 3 × 72 = 216
Divide by 2: 216/2 = 108
Move the decimal point one place to the left: 10.8
So 15% of 72 = 10.8.
