Launch Agenda 1 Abby and Zack are mixing red and yellow paint to make an orange color to paint their kitchen table. They each think they have the perfect

Launch

Agenda

1

Abby and Zack are mixing red and yellow paint to make an orange color to paint their kitchen table. They each think they have the perfect shade of orange.

Launch

Agenda

2

Zack’s orange paint is made by mixing 3 cups of red for every 5 cups of yellow.

This sounds like a ratio. What are ratios again?

Launch

Agenda

3

A ratio is a relationship between two or more quantities.

But, why would I want to use or think about a ratio?

Here’s a short video that will show how ratios are used in a few real life situations.

Here’s the definition:

http://www.bbc.co.uk/skillswise/video/ratio-and-proportion

http://www.bbc.co.uk/skillswise/video/ratio-and-proportion

Launch – Think, Pair, Share

Agenda

4

Zack’s orange paint is made by mixing 3 cups of red for every 5 cups of yellow.

Lefty – Tell Righty the ratio of red to yellow in Zack’s orange paint.Righty – Tell Lefty the ratio of yellow to red in Zack’s orange paint.

Partner Share

Class – What is the ratio of red to yellow in Zack’s orange paint?

3:5

3 to 5 or 3:5 or 3 5

Explore – Strategize

Agenda

5

Zack bought 24 cups of red paint.

How much yellow paint will Zack need to buy to make his shade of orange paint?

Write down in your notes any ideas you have about how to answer this question.

3:5

Explore – Mini-Lesson

Agenda

6

Before we solve Zack’s problem, let’s look at some simpler problems to get ready. Read this problem.

1. If there are 4 boys in the class, how many girls are there?

Example 1) The ratio of boys to girls in a class is 2 to 3.


Agenda

7

Let’s learn about a helpful tool for ratio problems that could help you with all sorts of ratio problems.




Agenda

8

We can use a tape diagram to solve ratio math problems.



Each box represents a number in the original ratio.

Now let’s look at the question.

New Tool: Tape Diagram

boys

girls


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9



boys

girls



If this tape shows 4 boys then…


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10



boys


girls 2


How many students are in one box? 2 2 This tape is 4 boys.So we put 4 above the tape.

4


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11



boys


girls


Important Rule:The number in each box must be the same for every tape.

2 22 2 2

4

?

We don’t yet know the number of girls so we put a ? for the length of that tape.


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12



boys


girls

Now we can answer the question.

6


4

?

2 22 2 2


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13

Let’s try another one.


2. If there are 8 girls in the class, how many boys are there?

First, draw the tapes.

Now let’s look at the question.


boys

girls

We can label what we know. 8 girls.We can put a question mark for what we don’t know.8

?


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14



boys


4 4girls

How many students does each box represent? 4


This makes 8 girls.

?

8


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15



boys 4


4

4 4girls

Remember:Every box must have the same quantity.

12

4

Can you answer the question using the diagram?


Advanced: Think of one way you could prove that the numbers in each box should be 4. Tell your partner.

?

8

Agenda

16

Let’s solve this problem using a tape diagram. We know: Zack’s orange paint is made by mixing 3 cups of red for every 5 cups of yellow.


And, we know: he bought 24 cups of red paint.

This is a 3:5 ratio of red to yellow.

Let’s draw the tapes.red

yellow

Let’s label the diagram.24

Now we can figure out how many cups each box represents. If 3 boxes are 24 then…

?

8 8 8

The question is: How many cups of yellow paint does Zack need to make his shade of orange paint?

Since every box must have the same quantity…

8 8 8 8 8

That means the answer is: 40 cups of yellow paint

Summary – Write in your notebook

Agenda

17

What is one thing you like about the tape diagrams as a tool?

What is one thing that is difficult?

Is there anything that is confusing about using tape diagrams as a tool?

Practice

Agenda

18

You will have 10 minutes to work on solving some ratio problems using the tape diagrams tool. You might feel a little confused and want to talk about it. Don’t worry – you will discuss it when you are finished.

http://www.online-stopwatch.com/

Documents

Launch Agenda 1 Abby and Zack are mixing red and yellow paint to make an orange color to paint their kitchen table. They each think they have the perfect