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Today we will review “Percents”. Let’s Warm up:. 1) ¾ x ¼ = 3/16. 2) 3/5 ÷ 1/4 =12/5 = 2 2/5. 3) 5/6 x 2/5 =1/3. 4) ½ ÷ ¾ =2/3. Modeling Percents. A percent (%) is a ratio that compares a number to 100 75% = 75 out of 100 Use a 10 x 10 grid to model percents Example: Model 18%
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Today we will review “Percents” CONFIDENTIAL
Let’s Warm up: 1) ¾ x ¼ = 3/16 2) 3/5 ÷ 1/4 =12/5 = 2 2/5 3) 5/6 x 2/5 =1/3 4) ½ ÷ ¾ =2/3 CONFIDENTIAL
Modeling Percents • A percent (%) is a ratio that compares a number to 100 • 75% = 75 out of 100 • Use a 10 x 10 grid to model percents • Example: Model 18% • 18% means 18 out of 100 • So, shade 18 out of the 100 squares CONFIDENTIAL
Your Turn! • Model 75% CONFIDENTIAL
Modeling Percents • Identify a percent that is modeled • There are 40 out of 100 squares shaded • So, the model shows 40% CONFIDENTIAL
Your Turn! • Identify the percent modeled. • 25% CONFIDENTIAL
Percents & Fractions • All percents can be written as fractions in simplest form • To write a percent as a fraction, • Write the percent as a fraction with a denominator as 100 • Then simplify • Write 50% as a fraction in simplest form • 50% means 50 out of 100 Write the percent as a fraction with a denominator of 100 Simplify. Divide the numerator and the denominator by the GCF, 50 CONFIDENTIAL
Percents & Fractions • Write 125% as a fraction in simplest form • 125% means 125 for every 100 CONFIDENTIAL
Your Turn! • Write 10% as a fraction. • 1/10 • Write 135% as a fraction. • 135/100 = 27/20 = 1 7/20 CONFIDENTIAL
Percents & Fractions • Write a Fraction as a Percent • Write 9/10 as a percent CONFIDENTIAL
Your Turn! • Write 3/5 as a percent • 60% CONFIDENTIAL
Percents & Decimals • Percents can be written as a decimal • To write a percent as a decimal • Rewrite the percent as a fraction with a denominator of 100 • Then write the fraction as a decimal • Write 56% as a decimal • Shortcut: Move the decimal point two places to the left, which is the same as dividing by 100 CONFIDENTIAL
Your Turn! • Write 0.3% as a decimal • 0.003 CONFIDENTIAL
Percents & Decimals • To write a decimal as a percent • Write the decimal as a fraction whose denominator is 100 • Then write the fraction as a percent • Write 0.38 as a percent • 0.38 = 38/100 Write the decimal as a fraction = 38% Write the fraction as a percent • Shortcut: Move the decimal place two places to the right, which is same as multiplying by 100 CONFIDENTIAL
Your Turn! • Write 0.189 as a percent • 18.9% CONFIDENTIAL
Percent of a Number • To find the percent of a number • Write the percent as a fraction and then multiply or • Write the percent as a decimal and then multiply • Find 5% of 300 • Method 1: Write the percent as a fraction CONFIDENTIAL
Percent of a Number • Method 2: Write the percent as a decimal • Use a model to check the answer. • The model confirms that 5% of 300 is 15 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% 0 30 60 90 120 150 180 210 240 270 300 CONFIDENTIAL
Your Turn! • Find 120% of 75. • 90 CONFIDENTIAL
Estimating with Percents • Sometimes when finding the percent of a number, an exact number is not needed • So, you can estimate • Commonly used Percents and their Fraction equivalents CONFIDENTIAL
Estimating with Percents • Estimate 52% of 298 • 52% is close to 50% or ½ • Round 298 to 300 • ½ of 300 is 150 • So, 52% of 298 is about 150 CONFIDENTIAL
Your Turn! • Estimate 60% of 27 • About 15 CONFIDENTIAL
Let us take a break! CONFIDENTIAL
Game Let us see how much you score on this one! • Click me CONFIDENTIAL
Assessment • Model 8% • Identify the percent modeled. 70% CONFIDENTIAL
Assessment • Write 97% as a fraction in simplest form. 97/100 • Write 3/5 as a percent. 60% • Write 32% as a decimal. 0.32 • Write 0.47 as a percent. 47% • Find 55% of 160. 88 • Estimate 48% of $76 ½ x 80 = $40 • Ian used 35% of his allowance to buy a book. If Ian received $20 for his allowance, how much did he use to buy the book? $7 • Melissa bought a sweatshirt that originally cost $30. If the sweatshirt was on sale for 25% off, what was the discount? $7.50 CONFIDENTIAL
Good Job! • You have learned a lot today!!! CONFIDENTIAL