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Ratio & Percent Power-Up!

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Lesson Plan

Ratio & Percent Power-Up!

Students will define ratios and percentages, understand their relationship, and apply them to solve practical problems such as calculating discounts and understanding survey data.

Understanding ratios and percentages is critical for making informed decisions in everyday life, from budgeting and shopping to interpreting news and statistics. Mastering these concepts equips students with essential mathematical literacy.

Audience

7th Grade Students

Time

30 minutes

Approach

Engaging visual aids, direct instruction, and guided practice.

Materials

Whiteboard or projector, Markers or pens, Ratio & Percent Power-Up! Slides, Ratio & Percent Practice Worksheet, and Ratio & Percent Practice Answer Key

Prep

Teacher Preparation

15 minutes

Step 1

Introduction: Hook and Prior Knowledge (5 minutes)

5 minutes

  • Hook: Begin by asking students: "Imagine you're at a store, and there's a '25% off' sale. What does that even mean? Or, if a recipe says '2 parts flour to 1 part sugar,' what are we talking about? Today, we're going to unlock the secrets behind these everyday numbers: ratios and percents!"
    * Connect to Prior Knowledge: Briefly review what students might already know about fractions or comparing quantities. Project Slide 1 and Slide 2.

Step 2

What are Ratios? (8 minutes)

8 minutes

  • Introduce Ratios: Explain that ratios compare two quantities. Provide examples. Use Slide 3 and Slide 4 to illustrate.
    * Guided Practice (Ratios): Work through a couple of simple ratio problems together as a class. For example, if there are 3 red apples and 5 green apples, what's the ratio of red to green? What's the ratio of red to total? (Use Slide 5)

Step 3

What are Percents? (8 minutes)

8 minutes

  • Introduce Percents: Explain that a percent is a ratio out of 100. Show how to convert fractions and decimals to percents. Use Slide 6 and Slide 7 to guide the discussion.
    * Guided Practice (Percents): Work through examples like calculating a simple percentage (e.g.,
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Slide Deck

Ratio & Percent Power-Up!

Unlocking the Secrets of Numbers!

Get ready to explore the amazing world of ratios and percentages!

Welcome students and generate excitement for the lesson. Briefly introduce the real-world relevance of ratios and percents.

Why Do We Care?

Ever seen a "25% Off" sign?

Or followed a recipe that says "2 parts flour to 1 part sugar"?

Today, we'll learn what these numbers mean and how to use them!

Ask students to think about where they might see ratios or percents in their daily lives. Encourage a short class discussion.

What's a Ratio?

A ratio compares two quantities.

  • Example: If you have 3 red marbles and 2 blue marbles, the ratio of red to blue is 3 to 2.
  • Think: How can we write this ratio?

Define what a ratio is and provide clear, simple examples. Emphasize that it's a comparison.

Ways to Write Ratios

Ratios can be written in a few ways:

  1. Using the word "to": 3 to 2
  2. Using a colon: 3:2
  3. As a fraction: 3/2

All these mean the same thing!

Show the different ways to write ratios. Emphasize that all three notations mean the same thing.

Ratio Practice!

In a basket of fruit, there are 4 apples and 6 bananas.

  • What is the ratio of apples to bananas?
  • What is the ratio of bananas to total fruit?

Present a simple practice problem for students to work on together or individually, then discuss the answer.

What's a Percent?

A percent means "out of one hundred" or "per one hundred."

  • The symbol for percent is %.
  • Example: 50% means 50 out of 100, or 50/100.

Define percent as 'out of one hundred' and explain its notation. Provide simple examples of what a percent represents.

Percents in Action!

How do percents relate to fractions and decimals?

  • Fraction to Percent: 1/2 = 50/100 = 50%
  • Decimal to Percent: 0.25 = 25/100 = 25%
  • Percent to Decimal: 75% = 75/100 = 0.75

Explain how to convert between fractions, decimals, and percents. Work through a couple of examples on the board if time permits.

Percent Practice!

If 20 out of 40 students in a class wear glasses, what percentage of students wear glasses?

Present a practice problem for students to apply their understanding of percentages.

You've Got the Power!

Today we learned:

  • Ratios compare quantities.
  • Percents are ratios out of 100.
  • Both are super useful in real life!

Keep an eye out for ratios and percents all around you!

Summarize the key takeaways from the lesson and encourage students to reflect on the importance of ratios and percents.

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Warm Up

Ratio & Percent Warm-Up

Instructions: Take a few minutes to answer the following questions to get your brain ready for ratios and percents!

  1. If there are 10 red cars and 5 blue cars in a parking lot, how many more red cars are there than blue cars?



  2. What does it mean if something is "half off" its original price? What percentage would that be?



  3. Think about your favorite sports team. Can you think of any numbers or statistics related to them that compare two things? (e.g., wins to losses, points scored per game, etc.)



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Cool Down

Ratio & Percent Cool-Down

Instructions: Please answer the following questions to show what you learned today. This will help your teacher understand what stuck with you!

  1. In your own words, what is a ratio? Give one example.



  2. What does the word "percent" mean? How is it related to a fraction?



  3. Imagine a survey found that 75% of students prefer pizza over tacos. What does that tell you about the students' preferences?



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Worksheet

Ratio & Percent Practice Worksheet

Instructions: Read each question carefully and show your work. Don't forget to use the skills we learned today!

Part 1: Ratios

  1. In a classroom, there are 15 boys and 10 girls.
    • What is the ratio of boys to girls? (Write in three ways)



    • What is the ratio of girls to the total number of students?



  2. A recipe calls for 2 cups of sugar for every 3 cups of flour. If you use 9 cups of flour, how many cups of sugar do you need?



  3. You are comparing two different brands of cereal. Brand A has 12 marshmallows for every 1 cup of cereal. Brand B has 18 marshmallows for every 2 cups of cereal. Which brand has a higher ratio of marshmallows to cereal?






Part 2: Percents

  1. Convert the following fractions to percentages:

    • 1/4 =

    • 3/5 =

    • 7/10 =

  2. Convert the following decimals to percentages:

    • 0.60 =

    • 0.05 =

    • 1.25 =

  3. A shirt originally costs $40. If it is on sale for 20% off, how much is the discount? What is the new price of the shirt?






  4. In a survey of 200 people, 70% said they like chocolate ice cream. How many people like chocolate ice cream?



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Answer Key

Ratio & Percent Practice Answer Key

Part 1: Ratios

  1. In a classroom, there are 15 boys and 10 girls.

    • What is the ratio of boys to girls? (Write in three ways)
      • Thought Process: The question asks for the comparison of boys to girls. There are 15 boys and 10 girls.
      • Answer: 15 to 10, 15:10, 15/10 (or simplified: 3 to 2, 3:2, 3/2)
    • What is the ratio of girls to the total number of students?
      • Thought Process: First, find the total number of students: 15 boys + 10 girls = 25 students. Then, compare girls to the total.
      • Answer: 10 to 25, 10:25, 10/25 (or simplified: 2 to 5, 2:5, 2/5)

  2. A recipe calls for 2 cups of sugar for every 3 cups of flour. If you use 9 cups of flour, how many cups of sugar do you need?

    • Thought Process: Set up a proportion: 2 cups sugar / 3 cups flour = x cups sugar / 9 cups flour. To get from 3 cups of flour to 9 cups, you multiply by 3. So, multiply the sugar by 3 as well.
    • Answer: 6 cups of sugar (2 * 3 = 6)

  3. You are comparing two different brands of cereal. Brand A has 12 marshmallows for every 1 cup of cereal. Brand B has 18 marshmallows for every 2 cups of cereal. Which brand has a higher ratio of marshmallows to cereal?

    • Thought Process: Compare the ratios. Brand A is 12 marshmallows/1 cup. Brand B is 18 marshmallows/2 cups, which simplifies to 9 marshmallows/1 cup. Comparing 12/1 to 9/1, Brand A has more marshmallows per cup.
    • Answer: Brand A has a higher ratio of marshmallows to cereal (12:1 compared to 9:1 for Brand B).

Part 2: Percents

  1. Convert the following fractions to percentages:

    • 1/4
      • Thought Process: Divide 1 by 4, then multiply by 100. (1 / 4 = 0.25 * 100 = 25%)
      • Answer: 25%
    • 3/5
      • Thought Process: Divide 3 by 5, then multiply by 100. (3 / 5 = 0.60 * 100 = 60%)
      • Answer: 60%
    • 7/10
      • Thought Process: Divide 7 by 10, then multiply by 100. (7 / 10 = 0.70 * 100 = 70%)
      • Answer: 70%

  2. Convert the following decimals to percentages:

    • 0.60
      • Thought Process: Multiply the decimal by 100.
      • Answer: 60%
    • 0.05
      • Thought Process: Multiply the decimal by 100.
      • Answer: 5%
    • 1.25
      • Thought Process: Multiply the decimal by 100.
      • Answer: 125%

  3. A shirt originally costs $40. If it is on sale for 20% off, how much is the discount? What is the new price of the shirt?

    • Thought Process: To find the discount, calculate 20% of $40 (0.20 * 40 = $8). To find the new price, subtract the discount from the original price ($40 - $8 = $32).
    • Answer: The discount is $8. The new price of the shirt is $32.

  4. In a survey of 200 people, 70% said they like chocolate ice cream. How many people like chocolate ice cream?

    • Thought Process: To find the number of people, calculate 70% of 200 (0.70 * 200 = 140).
    • Answer: 140 people like chocolate ice cream.
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