5 Minute Check Find. Round to the nearest tenth, if necessary. Complete in your notes. 1. 9 is what percent of 72? 2. What percent of 96 is 24? 3. 17 is 40% of what number? 4. 80% of what number is 64?

5 Minute Check Find. Round to the nearest tenth, if necessary. Complete in your notes. 1. 9 is what percent of 72?

5 Minute Check Find. Round to the nearest tenth, if necessary. Complete in your notes. 1. 9 is what percent of 72? part = percent (in decimal form) x whole 9 = p · 72 72 72 1 = p 8 12.5% = p .125 8)1.00 -8 20 -16 40

5 Minute Check Find. Round to the nearest tenth, if necessary. Complete in your notes. 2. What percent of 96 is 24?

5 Minute Check Find. Round to the nearest tenth, if necessary. Complete in your notes. 2. What percent of 96 is 24? part = percent (in decimal form) x whole 24 = p · 96 96 96 1 = p 4 25% = p

5 Minute Check Find. Round to the nearest tenth, if necessary. Complete in your notes. 3. 17 is 40% of what number?

5 Minute Check Find. Round to the nearest tenth, if necessary. Complete in your notes. 3. 17 is 40% of what number? 17 = .40 · w .40 .40 42.5 = w 42.5 40)1700.0 -160 100 -80 200

5 Minute Check Find. Round to the nearest tenth, if necessary. Complete in your notes. 4. 80% of what number is 64?

5 Minute Check Find. Round to the nearest tenth, if necessary. Complete in your notes. 4. 80% of what number is 64? 64 = .80 · w .80 .80 80 = w 80.0 80)6400.0 -640 00

Lesson 7.2.5 Percent of Change Monday, Feb 2 Lesson 7.2.5 Percent of Change

Solve One-Step Inequalities

Solve One-Step Inequalities

Solve One-Step Inequalities

Solve One-Step Inequalities

Solve One-Step Inequalities

Solve One-Step Inequalities

Percent of Change Objective: To understand the percent of change and percent of error.

Percent of Change A percent of change is a ratio that compares the change in quantity to the original amount. Write this down.

Percent of Change Yusuf bought a DVD recorder for $280. Now it is on sale for $210. Find the percent of change in the price. How to Find the Percent of Change. Step 1 – Find the change. Changed number minus original number.

Percent of Change Yusuf bought a DVD recorder for $280. Now it is on sale for $210. Find the percent of change in the price. $210 - $280 = - $70 How to Find the Percent of Change. Step 1 – Find the change. Changed number minus original number.

Percent of Change Yusuf bought a DVD recorder for $280. Now it is on sale for $210. Find the percent of change in the price. $210 - $280 = - $70 How to Find the Percent of Change. Step 2 – Create a ratio with the change over the original amount.

Percent of Change Yusuf bought a DVD recorder for $280. Now it is on sale for $210. Find the percent of change in the price. $210 - $280 = - $70 − $70 $280 How to Find the Percent of Change. Step 2 – Create a ratio with the change over the original amount.

Percent of Change Yusuf bought a DVD recorder for $280. Now it is on sale for $210. Find the percent of change in the price. $210 - $280 = - $70 −$70 $280 How to Find the Percent of Change. Step 3 – Simplify.

−$70 $280 = - 1 4 Percent of Change Yusuf bought a DVD recorder for $280. Now it is on sale for $210. Find the percent of change in the price. $210 - $280 = - $70 −$70 $280 = - 1 4 How to Find the Percent of Change. Step 3 – Simplify.

−$70 $280 = - 1 4 Percent of Change Yusuf bought a DVD recorder for $280. Now it is on sale for $210. Find the percent of change in the price. $210 - $280 = - $70 −$70 $280 = - 1 4 How to Find the Percent of Change. Step 4 – Convert to a percent.

−$70 $280 = - 1 4 = -25% Percent of Change Yusuf bought a DVD recorder for $280. Now it is on sale for $210. Find the percent of change in the price. $210 - $280 = - $70 −$70 $280 = - 1 4 = -25% The price decreased by 25% How to Find the Percent of Change. Step 4 – Convert to a percent. .25 = 25% 4)1.00 -8 20

Percent of Change Find the percentage of change from 10 yards to 13 yards. Step 1 - ?

Percent of Change Find the percentage of change from 10 yards to 13 yards. 13 - 10 = 3 Step 2 - ?

3 10 Step 3 - ? Percent of Change Find the percentage of change from 10 yards to 13 yards. 13 - 10 = 3 3 10 Step 3 - ?

3 10 Step 4 - ? Percent of Change Find the percentage of change from 10 yards to 13 yards. 13 - 10 = 3 3 10 Step 4 - ?

3 10 = 30% increase Percent of Change Find the percentage of change from 10 yards to 13 yards. 13 - 10 = 3 3 10 = 30% increase .30 = 30% 10)3.00 -30

Do this on your own. Percent of Change The price of a radio was $120. It is on sale for $102. What is the percent of change in the price of the radio? Do this on your own.

−18 120 =- 3 20 = - 15% A 15% decrease. Percent of Change The price of a radio was $120. It is on sale for $102. What is the percent of change in the price of the radio? 102 - 120 = -18 −18 120 =- 3 20 = - 15% A 15% decrease. .15 = 15% 20)3.00 -20 100

Percent of Change 66 feet to 26.4 feet. Do this on your own.

−39.6 66 = - 60% Percent of Change 66 feet to 26.4 feet. 26.4 - 66= - 39.6 −39.6 66 = - 60% A 60% decrease .6 = 60% 66)39.6 -396

Percent of Change Find the percent of change in the perimeter of the square if the sides decreased by 1 inch. 3 in.

8 – 12 = - 4 − 4 12 = - 33 1 3 % Percent of Change Find the percent of change in the perimeter of the square if the sides decreased by 1 inch. SQ 1 SQ 2 4(3) =12 in 4(2) = 8 in 3 in. 8 – 12 = - 4 − 4 12 = - 33 1 3 % A 33 1 3 % decrease

Percent of Change Find the percent of change in the perimeter of the square if the sides decreased by 1 inch. What is the change in area? 3 in.

4 – 9 = - 5 − 5 9 = - 55.5% Percent of Change Find the percent of change in the perimeter of the square if the sides decreased by 1 inch. What is the change in area? SQ 1 SQ 2 3·3 =9 in² 2·2 = 4 in² 3 in. 4 – 9 = - 5 − 5 9 = - 55.5% A 56 % decrease .55 9)5.0 -45 50

Percent of Change Use the graph shown to find the percent of change in CD sales from 2011 to 2012. Round to the nearest tenth. Do this on your own.

Percent of Change Use the graph shown to find the percent of change in CD sales from 2011 to 2012. Round to the nearest tenth. = −12 283 = -0.0424 = -4.2% A 4.2% decrease.

Percent of Change A percent of error is a ratio that compares inaccuracy of an estimate, or amount of error, to the actual amount. Write this down. Generally, the percent of error does not determine whether it is an increase or decrease.

Percent of Change Finding the percent of error is similar to finding the percent of change.

Percent of Change Ahmed wants to practice free throws. He estimates the distance from the free throw line to the hoop and marks it with chalk. Ahmed’s estimate was 13.5 feet. The actual distance should be 15 feet. Find the percent error.

Percent of Change Ahmed wants to practice free throws. He estimates the distance from the free throw line to the hoop and marks it with chalk. Ahmed’s estimate was 13.5 feet. The actual distance should be 15 feet. Find the percent error. = 1.5 𝑓𝑡 15 𝑓𝑡 = 0.1 = 10%

Percent of Change Find the percent error if the estimate was $285 and the actual amount was $300. Do this on your own.

Percent of Change Find the percent error if the estimate was $285 and the actual amount was $300. = 15 300 = 0.05 = 5%

Percent of Change Each week, Mr. Jones goes to the grocery store. Mr. Jones estimates he will spend $120 when he goes to the grocery store this week. He actually spends $94. What is the percent of error rounded to the tenth? Do this on your own.

Percent of Change Each week, Mr. Jones goes to the grocery store. Mr. Jones estimates he will spend $120 when he goes to the grocery store this week. He actually spends $94. What is the percent of error rounded to the tenth? = 26 94 = 0.2765 = 27.7%

Percent of Change Johanna’s parents give her $10 per week for lunch money. The costs of two sound systems were decreased by $10. The original costs of the systems were $90 and $60. Without calculating, which had the greater percent of decrease? Explain.

Percent of Change Johanna’s parents give her $10 per week for lunch money. The costs of two sound systems were decreased by $10. The original costs of the systems were $90 and $60. Without calculating, which had the greater percent of decrease? Explain. The $60 system. $10 is a greater part of $60 than $90.

Percent of Change Johanna’s parents give her $10 per week for lunch money. Without using a calculator, arrange the following from greatest to least value. Justify your answer. 20% of 100, 20% of 500, 5% of 100

Percent of Change Johanna’s parents give her $10 per week for lunch money. Without using a calculator, arrange the following from greatest to least value. Justify your answer. 20% of 100, 20% of 500, 5% of 100

Percent of Change Agenda Notes Homework Practice 7.2.5 Due Tuesday, Feb 3 Chapter 7.2/7.3 Test - Tuesday, Feb 10