Find a percentage or work out the percentage given numbers and percent values. Use percent formulas to figure out percentages and unknowns in equations. Add or subtract a percentage from a number or solve the equations. Show
How to Calculate PercentagesThere are many formulas for percentage problems. You can think of the most basic as X/Y = P x 100. The formulas below are all mathematical variations of this formula. Let's explore the three basic percentage problems. X and Y are numbers and P is the percentage:
Read on to learn more about how to figure percentages. 1. How to calculate percentage of a number. Use the percentage formula: P% * X = YExample: What is 10% of 150?
2. How to find what percent of X is Y. Use the percentage formula: Y/X = P%Example: What percent of 60 is 12?
3. How to find X if P percent of it is Y. Use the percentage formula Y/P% = XExample: 25 is 20% of what number?
Remember: How to convert a percentage to a decimal
Remember: How to convert a decimal to a percentage
Percentage ProblemsThere are nine variations on the three basic problems involving percentages. See if you can match your problem to one of the samples below. The problem formats match the input fields in the calculator above. Formulas and examples are included.
Related CalculatorsFind the change in percentage as an increase or decrease using the Percentage Change Calculator. Solve decimal to percentage conversions with our Decimal to Percent Calculator. Convert from percentage to decimals with the Percent to Decimal Calculator. If you need to convert between fractions and percents see our Fraction to Percent Calculator, or our Percent to Fraction Calculator. ReferencesWeisstein, Eric W. "Percent." From MathWorld -- A Wolfram Web Resource. Learn the basics of how to calculate percentages of quantities in this easy lesson! To find a percentage of any number, use this generic guideline of TRANSLATION: Change the percentage into a decimal, and the word "of" into multiplication. See many examples below. The concepts and ideas of this lesson are also explained in this video:
1. "Translate" the expressions into multiplication by a decimal. Calculate.
2. "Translate" the other way: write the multiplications as expressions of "percentage of the number".
3. Use a calculator to find percentages of these quantities. a. 17% of $4500 b. 67% of 27 m 4. Use mental math to find percentages of these quantities. 5. a. A lake has a 30-km long shoreline. 6% of it is sandy beach. What percentage of the shoreline is not sandy beach? 6. Twenty percent of a university’s 4,000 students have a scholarship. a. What percent of the students do not have a scholarship? b. How many students have a scholarship? 8. Identify the errors that Gladys made. Then find the correct answer. Find 80% of 50. Gladys’s solution: 9. Find the expressions with the same value as 20% of $620.
11. The table below shows Andy’s usage of time in one day. a. Calculate the time he spent in each activity. b. Label the sections in the circle graph with the name of each activity. Andy’s Usage of Time
Percent – free lesson Percentage of a number using mental math – free lesson How to calculate percentages – free lesson Basics of percent of change – free lesson Interactive fraction, decimal and percentage tool This tool shows you a fraction visually (bar or pie) and converts the fraction into a percentage and decimal. You can show or hide the equivalent percentage and decimal. /interactives/fraction_decimal_percentage.php This lesson is taken from Maria Miller's book Math Mammoth Percent, and posted at www.HomeschoolMath.net with permission from the author. Copyright © Maria Miller. |