Learn the basics of exactly how to calculate percentages of quantities in this easy lesson! To find a percentage of any type of number, usage this generic reminder of TRANSLATION: readjust the percentage into a decimal, and also the word "of" into multiplication. See countless examples below.

You are watching: 80 of what number is 160**The concepts and ideas of this class are also explained in this video:**

You have learned that to find 1% of a number way finding 1/100 the it. Similarly, recognize 60% that a number method finding 60/100 (or 6/10) of it.In this expressions, words “of” translates into multiplication:1% the 90 → 1% × 90& 60% the $700 → 60% × $700.We can additionally write those percentages together decimals:1% that 90 → 0.01 × 90 60% that $700 → 0.6 × $700. This gives us another method to calculation the portion of a number (or percent of part quantity): |

To calculation a percent of some number, change the percentage into a decimal, and the native "of" into multiplication. |

Example 1. Find 70% the 80.Following the shortcut, we compose this as 0.7 × 80. Remember that in decimal multiplication, friend multiply together if there were no decimal points, and the price will have actually as many “decimal digits” come the appropriate of the decimal suggest as the total number of decimal digits of every one of the factors. So as soon as you main point 0.7 × 80, think of multiply 7 × 80 = 560. Because 0.7 has one decimal digit, and 80 has none, the answer has one decimal digit: 56.0 Thus, 0.7 × 80 = 56. You can additionally use “common sense” to reason it through logically: 0.7 × 80 should be much less than 80, yet much more than 1/2 the 80, which is 40. Because 7 × 8 = 56, you understand that the answer must be 56—not 5.6 or 560. |

Example 2. Find 3% that $4,000.First compose it as 0.03 × $4,000. Climate multiply 3 × $4,000 = $12,000. Finally put the decimal point where it gives the answer 2 decimal digits: $120.00. |

Example 3. Find 23% of 5,500km.Write the expression together 0.23×5,500km and also use a calculator to calculation the product. The answer is 1,265km. This answer provides sense because 10% of 5,500km is 550km, for this reason 20% is 1,100km. Hence 1,265km together 23% the 5,500km is a reasonable answer. |

**1. "Translate" the expressions into multiplication through a decimal. Calculate.**

a. 20% the 70______ × ______ = ______ | b. 90% of 50______ × ______ = ______ | c. 9% the 3,000______ × ______ = ______ |

a. 0.6 × 50_____% the ______ = ______ | b. 0.03 × $400_____% of ______ = ______ | c. 0.08 × 6_____% the ______ = ______ |

**a.** 17% the $4500

**b.** 67% of 27 m

4. Use mental math to uncover percentages of these quantities.

a. 25% the 240 mi |

5. **a.** A lake has a 30-km lengthy shoreline. 6% of that is sandy beach. What percentage of the coastline is no sandy beach?

6. Twenty percent that a university’s 4,000 students have actually a scholarship.

** a.** What percent that the students do not have a scholarship?

** b. **How countless students have actually a scholarship?

8. Recognize the errors the Gladys made. Then discover the correct answer.

9. Discover the expressions v the same value as 20% of $620.

0.02 × $620 | $620 ÷ 5 |

$620 ÷ 10 × 2 | 2 × $62 |

1 5 | × $620 |

** a.** Calculate the moment he invested in every activity.** round the minute to the nearest minute.**

** b.See more: Is 85 A Prime Or Composite Number ? Is 85 A Prime Or Composite Number** label the sections in the circle graph v the name of each activity.

**Andy’s usage of Time**

Activity | Percent | Minutes | Hours/minutes |

Sleep | 38% | ||

School | 21% | ||

Soccer | 10% | 144 | 2 h 24 min |

Play | 11% | ||

Eating | 9% | ||

Chores | 9% | ||

Hygiene | 2% | ||

TOTAL | 100% | 1440 | 24 hours |

### See also

Percent – cost-free lessonPercentage that a number using mental math – complimentary lesson

How to calculate percentages – free lesson

Basics of percent of readjust – totally free lesson

**Interactive fraction, decimal and percentage tool****This tool shows you a portion visually (bar or pie) and converts the fraction into a percentage and also decimal. You can show or hide the tantamount percentage and also decimal./interactives/fraction_decimal_percentage.php**

Place worth Grade 1Grade 2Grade 3Grade 4 | Add & subtract lessonsGrade 1Grade 2Grade 3 | Multiplication great 3Grade 4 |

Division class 3Grade 4 Divisibility | Fraction Lessons adding mixed numbers | Geometry lessons |

Decimals Lessons main point a decimal through a whole number | Percents great | General |