Reviewed by Claire Smizer
What is 15% of 40?
Answer: 15% of 40 is 6
Finding a percentage of a number is a fundamental math skill often used in daily life. To determine 15% of 40, you calculate what portion 15 out of every 100 parts of 40 is, or in other words, multiply 40 by 15 percent expressed as a decimal.
Methods
Math Tutor Explanation Using the Percent-to-Decimal Method
Convert the percentage to a decimal and multiply by the whole number.
Step 1: Step 1: Convert 15% to a decimal by dividing 15 by 100
Step 2: Step 2: Multiply 0.15 (the decimal) by 40 to get the answer
Math Tutor Explanation Using Mental Math
Break 15% down as 10% plus 5% to quickly estimate without a calculator.
Step 1: Step 1: Find 10% of 40 by moving the decimal one place left (10% of 40 is 4)
Step 2: Step 2: Find 5% of 40 by halving 10%, so 5% of 40 is 2
Step 1:
Step 2:
Math Tutor suggests: Practice More Percentage Problems
Keep building your skills with more exercises involving percentages of numbers and related calculations.
FAQ on Calculating Percentages
How do you turn a percentage into a decimal?
Divide the percentage by 100, so 15% becomes 0.15.
What is the general formula for finding a percentage of a number?
Multiply the number by the percentage expressed as a decimal.
Can percentages be greater than 100%?
Yes, percentages above 100% mean more than the whole, like 150% of 20 is 30.
Is it possible to find the percentage if you know the part and the whole?
Yes, divide the part by the whole and multiply by 100 to get the percentage.
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