Learn the basics of exactly how to calculate percentages of quantities in this basic lesson! To discover a percent of any kind of number, usage this generic pointer of TRANSLATION: readjust the percentage into a decimal, and also the word "of" right into multiplication. See countless examples below.

You are watching: 21 is 60 percent of what number**The concepts and also ideas of this great are additionally explained in this video:**

You have actually learned that to find 1% of a number way finding 1/100 that it. Similarly, finding 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% of $700 → 60% × $700.We can additionally write those percentages as decimals:1% of 90 → 0.01 × 90 60% that $700 → 0.6 × $700. This gives us another way to calculation the portion of a number (or percentage of part quantity): |

To calculation a portion of some number, readjust the percentage into a decimal, and the indigenous "of" right into multiplication. |

Example 1. Find 70% that 80.Following the shortcut, we compose this as 0.7 × 80. Remember that in decimal multiplication, you multiply together if there were no decimal points, and also the price will have as plenty of “decimal digits” to the right of the decimal suggest as the total number of decimal digits of all of the factors. So when you multiply 0.7 × 80, think of multiply 7 × 80 = 560. Since 0.7 has actually one decimal digit, and 80 has actually none, the answer has one decimal digit: 56.0 Thus, 0.7 × 80 = 56. You can also use “common sense” to reason it with logically: 0.7 × 80 should be less than 80, yet more than 1/2 of 80, i beg your pardon is 40. Due to the fact that 7 × 8 = 56, you understand that the answer need to be 56—not 5.6 or 560. |

Example 2. Find 3% of $4,000.First create it together 0.03 × $4,000. Climate multiply 3 × $4,000 = $12,000. Ultimately put the decimal suggest where it gives the answer 2 decimal digits: $120.00. |

Example 3. Find 23% of 5,500km.Write the expression as 0.23×5,500km and use a calculator to calculation the product. The answer is 1,265km. This answer renders sense since 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 by a decimal. Calculate.**

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

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

**a.** 17% the $4500

**b.** 67% the 27 m

4. Use psychological math to discover percentages of this quantities.

a. 25% of 240 mi |

5. **a.** A lake has a 30-km long shoreline. 6% of it is sandy beach. What percent of the coast is not sandy beach?

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

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

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

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

9. Find the expressions through the same value as 20% that $620.

0.02 × $620 | $620 ÷ 5 |

$620 ÷ 10 × 2 | 2 × $62 |

1 5 | × $620 |

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

** b.See more: Closest Airport To Research Triangle Park Nc, Travel & Hotel** brand the sections in the one graph v the surname of every activity.

**Andy’s consumption 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 – complimentary lessonPercentage of a number using mental math – totally free lesson

How to calculate percentages – free lesson

Basics of percent of change – totally free lesson

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

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

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

Decimals Lessons multiply a decimal through a entirety number | Percents class | General |