PERCENT OF A NUMBER Copyright©Ed2NetLearning.Inc

Prerequisite Skill Multiply: 1 x 100 - 20 5 ½ x 3,000 - 1500 Copyright©Ed2NetLearning.Inc

Objectives To find the percent of a number To express one number (x) as the percent of some other number (y) Copyright©Ed2NetLearning.Inc

Percent of a Number To find the percent of a number, we can use one of the following methods: Write the percent as a fraction and then multiply or Write the percent as a decimal and then multiply. Copyright©Ed2NetLearning.Inc

Find the Percent of a Number Find 5 % of 200 Method – 1 5 % = 5 or 1 100 20 1 of 200 = 1 x 200 20 20 = 10 Method – 2 5 % = 0.05 0.05 of 200 = 0.05 x 200 = 10 Copyright©Ed2NetLearning.Inc

Find the percent of a number Find 120 % of 75 Method – 1 120 % of 75 = 120 x 75 100 = 6 x 75 5 = 90 Method – 2 120 % of 75 = 1.2 of 75 = 1.2 x 75 = 90 Copyright©Ed2NetLearning.Inc

Practice Problems Find the percent of each number 15 % of 90 = 1350 Copyright©Ed2NetLearning.Inc

Express a number as the percent of another number To express one number (quantity), say a, as the percent of some other number (quantity). Say b, we have to find a x 100 % b Copyright©Ed2NetLearning.Inc

Examples Express 70 as the percent of 280 . . . 70 as the percent of 280 = 70 x 100 % 280 = 25 % Copyright©Ed2NetLearning.Inc

Example - 2 What percent of 80 is 32? Direct Method: The required percent = 32 x 100 % 80 = 40 % Alternative Method: Let y % of 80 = 32  y x 80 = 32 100  y = 32 x 100 = 40 % Copyright©Ed2NetLearning.Inc

Exercise Express 24 as the percentage of 30 80 % 2. Find, 45 is what percent of 54? – 83 1 % 3 3. 126 is 35 % of a certain number; find the number - 360 Express 2/3 as the percent of 5/9 120% 5. Express 1/5 as the percent of ¼ 80 % Copyright©Ed2NetLearning.Inc

WORD PROBLEMS In an election, a candidate secured 43 % of 35000 votes polled and lost the election. Find the votes secured by the lost candidate 43 x 35000 = 43 x 350 100 = 15050 votes Copyright©Ed2NetLearning.Inc

Word Problems 20 % of a number is 75. find the number 100 Number = 75 x 100 20 = 75 x 5 = 375 Copyright©Ed2NetLearning.Inc

Now your turn A man spends 65 % of his salary and saves $525 per month. Find his salary per month the man spends 65 % of his salary he saves = (100 – 65) = 35 % of salary 35 % of salary = $ 525 35 x salary = $ 525 100 Salary = $ 525 x 100 35 = $ 1500. Copyright©Ed2NetLearning.Inc

Question 2. Out of 800 oranges, 50 are rotten. Find the percentage of good oranges number of rotten oranges = 50 number of good oranges = 800 – 50 = 750 percentage of good oranges = 750 x 100 800 = 93 ¾ % Copyright©Ed2NetLearning.Inc

Review To find the percent of a number, we can use one of the following methods: Write the percent as a fraction and then multiply or Write the percent as a decimal and then multiply. Copyright©Ed2NetLearning.Inc

Assessment 70 % of 280 = 196 40 % of 180 = 72 23 % of 15 = 3.45 Copyright©Ed2NetLearning.Inc

Assessment 6. 75 % of $ 320 - $ 240 7. 5 % sales tax on a sale is $ 90. what is the amount of sale? - $1800 8. If 30 % of a sum of money is $ 270. what is the total sum of money ? - $ 900 9.Find 12 ½ % of 144 kilogram of rice? 18kilogram 10. If 14 % of a number is 105. Find the number? - 750 Copyright©Ed2NetLearning.Inc

Great Job! Copyright©Ed2NetLearning.Inc