Slide 1 / 194 Slide 2 / 194 Table of Contents Ratios as Percents Decimals as Percents Percents as Decimals Fractions as Percents Percents Percents as Fractions Fractional Parts and Equivalent Names Relating Fractions, Decimals and Percents Three types of Percent Problems Percent of Change Applied Percent of Decrease Applied Percent of Increase Real-life Application Problems Slide 3 / 194 Slide 4 / 194 Ratios as Percents What fraction of each grid is shaded? ___ ___ ___ 100 100 100 Return to table of contents Slide 5 / 194 Slide 6 / 194 The fractions and ratios can also be written as percentages. What is the ratio of shaded boxes to total boxes? Percent means per 100. 10 Fraction: ______ to _______ ______ to _______ ______ to _______ 100 Fraction: Fraction: Ratio: 10 to 100 Ratio: Ratio: Percent: 10% Percent: Percent:
Slide 7 / 194 Slide 8 / 194 What percent of the grid is shaded? Use the black stylus to shade 5% Use the green stylus to shade 20% of the grid. of the grid. How many squares will you shade? How many squares will you shade? Slide 9 / 194 Slide 10 / 194 1 1% of the grid is shaded. True False Use the red stylus to shade 100% of the grid. How many squares will you shade? 100% of something represents how much? Slide 11 / 194 Slide 12 / 194 2 100% of the grid is shaded. 3 What percent of the grid is shaded? True False
Slide 13 / 194 Slide 14 / 194 5 15 is the same as what percent? 4 6 to 100 is the same as what percent? 100 600% A 150% A 60% 100% B B 6% 15% C C D 100% D 5% Slide 15 / 194 Slide 16 / 194 6 Express the ratio as a percent. 7 Express the ratio as a percent. 57 out of 100 67 lacrosse team members in 100 students Slide 17 / 194 Slide 18 / 194 0 8 Express the ratio as a percent. $18 per $100 Writing Decimals as Percents decimals p e r c Return to table e of contents n t s
Slide 19 / 194 Slide 20 / 194 Writing decimals as percents... Writing decimals as percents... Multiply by 100 and add the percent symbol. Multiply by 100 and add the percent symbol. Example 1: Example 2: 0.09 = 0.09 100 0.75 = 0.75 100 = 9% = 75% Remember Remember To multiply a # by 100, move the decimal two 0.09 To multiply a # by 100, move the decimal two places to the RIGHT. places to the RIGHT. 0.75 Slide 21 / 194 Slide 22 / 194 Writing decimals as percents... Writing decimals as percents... Multiply by 100 and add the percent symbol. Multiply by 100 and add the percent symbol. Example 4: Example 3: 0.4 = 0.4 100 0.007 = 0.007 100 = 40% = 0.7% Remember To multiply a # by 100, move the decimal two Remember places to the RIGHT. 0.4 To multiply a # by 100, move the decimal two places to the RIGHT. 0.007 Slide 23 / 194 Slide 24 / 194 Writing decimals as percents... Writing decimals as percents... Multiply by 100 and add the percent symbol. Multiply by 100 and add the percent symbol. Example 5: Example 6: 1.49 = 1.49 100 8 = 8 100 = 149% = 800% Remember To multiply a # by 100, move the decimal two Remember places to the RIGHT. To multiply a # by 100, move the decimal two 1.49 8 places to the RIGHT.
Slide 25 / 194 Slide 26 / 194 10 Write the decimal as a percent: 9 Write the decimal as a percent: 1.3 0.45 130% 45% Slide 27 / 194 Slide 28 / 194 11 Write the decimal as a percent: 12 Write the decimal as a percent: 0.008 5 500% .8% Slide 29 / 194 Slide 30 / 194 13 Write the decimal as a percent: .2 Writing Percents as Decimals 20% percent decimal Return to table of contents
Slide 31 / 194 Slide 32 / 194 Writing percents as decimals... Writing percents as decimals... Divide by 100 and remove the percent symbol. Divide by 100 and remove the percent symbol. Example 2: Example 1: 100 8% = 8% 28% = 28% 100 = 0.08 = 0.28 Remember Remember To divide a # by 100, move the decimal two To divide a # by 100, move the decimal two places to the LEFT. places to the LEFT. 8% 28% Slide 33 / 194 Slide 34 / 194 Writing percents as decimals... Writing percents as decimals... Divide by 100 and remove the percent symbol. Divide by 100 and remove the percent symbol. Example 4: Example 3: 100 375% = 375% 0.4% 100 0.4% = = = 3.75 0.004 Remember Remember To divide a # by 100, move the decimal two To divide a # by 100, move the decimal two places to the LEFT. 0.4% places to the LEFT. 375% Slide 35 / 194 Slide 36 / 194 14 Write the percent as a decimal: Writing percents as decimals... Divide by 100 and remove the percent symbol. 2% Example 5: 0.235 = .02 Remember To divide a # by 100, move the decimal two places to the LEFT.
Slide 37 / 194 Slide 38 / 194 15 Write the percent as a decimal: 16 Write the percent as a decimal: 658% 0.019% .00019 6.58 Slide 39 / 194 Slide 40 / 194 17 Write the percent as a decimal: 18 Write the percent as a decimal: 4.3% .5% .043 0.005 Slide 41 / 194 Slide 42 / 194 19 Write the percent as a decimal: 20 Write the percent as a decimal: 0.725 0.2975
Slide 43 / 194 Slide 44 / 194 Writing fractions as percents... Write an equivalent fraction with a denominator Writing Fractions as of 100. Percents percents Example 1: 25 3 3 x x 75 = = 4 100 100 4 100 n s t i o a c f r 25 Return to table of contents 75% Slide 45 / 194 Slide 46 / 194 Writing fractions as percents... Writing fractions as percents... Write an equivalent fraction with a denominator Write an equivalent fraction with a denominator of 100. of 100. Example 2: Example3: 25 20 9 9 4 4 x x x x 225 80 = = = = 5 4 100 100 100 100 100 4 100 5 20 25 225% 80% Slide 47 / 194 Slide 48 / 194 Writing fractions as percents... 21 Write the fraction as a percent: 19 Write an equivalent fraction with a denominator 20 of 100. Example 4: 6 3 x 3 x 0.5 = = 100 100 95% 600 600 100 6 0.5%
Slide 49 / 194 Slide 50 / 194 22 Write the fraction as a percent: 23 Write the fraction as a percent: 8 9 1000 100 8% .9% Slide 51 / 194 Slide 52 / 194 24 Write the fraction as a percent: 25 Write the fraction as a percent: 5 3 2 500 .6% 250% Slide 53 / 194 Slide 54 / 194 To write any fraction as a percent: To write any fraction as a percent: METHOD 2: METHOD 1: Write a proportion with the fraction as the first ratio and Express the fraction as a decimal 100 as the denominator of the second ratio. and then express the decimal as a percent. Solve using cross products. Example 5: Example 5: 7 0.875 0.875 100 8 8 7.000 87.5%
Slide 55 / 194 Slide 56 / 194 To write any fraction as a percent: To write any fraction as a percent: METHOD 2: METHOD 1: Write a proportion with the fraction as the first ratio and Express the fraction as a decimal and then express 100 as the denominator of the second ratio. the decimal as a percent. Solve using cross products. Example 6: Example 6: 12 1.333 1.333 100 9 9 12.000 133.3% 1 % 133 3 = = Slide 57 / 194 Slide 58 / 194 To write any fraction as a percent: METHOD 1: Express the fraction as a decimal and then express the decimal as a percent. Don't forget to add the whole number! Example 7: 5 0.625 3 3 100 3.625 8 8 5.000 362.5% Slide 59 / 194 Slide 60 / 194 27 Write the fraction as a percent. Round to the 26 Write the fraction as a percent: nearest whole percent. 5 4 8 7 57% 62.5%
Slide 61 / 194 Slide 62 / 194 28 Write the fraction as a percent: 29 Write the fraction as a percent: 3 2 3 5 500 360% .4% Slide 63 / 194 Slide 64 / 194 30 Write the fraction as a percent: Writing Percents 9 as Fractions 2 percents Return to table of contents fractions 450% Slide 65 / 194 Slide 66 / 194 Writing percents as fractions... Writing percents as fractions... Express the % as a fraction with a denominator Express the % as a fraction with a denominator of 100, then simplify. of 100, then simplify. Example 2: Example 1: 120 1 75 3 120% = = 1 = 75% = 100 5 100 4
Slide 67 / 194 Slide 68 / 194 Writing percents as fractions... Writing percents as fractions... Express the % as a fraction with a denominator of 100, Express the % as a fraction with a denominator then simplify. of 100, then simplify. Example 4: 9 2.25 225 9 Example 3: 1 4 % = = = 2 = 4 10,000 400 100 100 0.3 3 0.3% = = Multiply by 100 to eliminate the decimal 100 1000 Multiply by 10 to eliminate the decimal Slide 69 / 194 Slide 70 / 194 Writing percents as fractions...another way Express the % as a fraction with a denominator of 100, then simplify. Example 4: Convert the percent to a fraction. Divide the numerator by the denominator (100). Simplify. Slide 71 / 194 Slide 72 / 194 32 Write the percent as a fraction in 31 Write the percent as a fraction in simplest form: simplest form: 110% 40% 11 2 10 5
Slide 73 / 194 Slide 74 / 194 34 Write the percent as a fraction in 33 Write the percent as a fraction in simplest form: simplest form: 8% 0.5% 2 25 1 200 Slide 75 / 194 Slide 76 / 194 35 Write the percent as a fraction in simplest 36 Write the percent as a fraction in simplest form: form: 3 9 % 8 1 5 % 3 4 3 32 75 Slide 77 / 194 Slide 78 / 194 37 Write the percent as a fraction in simplest form: 4 54 % 7 Fractional Parts and Equivalent Names 191 350 Return to table of contents
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