## Classroom Video: Staircase of Complexity - Section 3: Comparing Measurements

*Classroom Video: Staircase of Complexity*

# Converting Measurements Using Ratios Day 2

Lesson 7 of 21

## Objective: SWBAT: • Use ratios to convert measurement units using multiplication or division. • Convert measurements between the customary and metric system. • Apply knowledge of measurement conversions to solve word problems.

## Big Idea: Which building is the world’s tallest building? Students use ratios to convert measurements between customary and metric systems. Students apply this knowledge to word problems.

*50 minutes*

#### Do Now

*3 min*

See my **Do Now** in my Strategy folder that explains my beginning of class routines.

Often, I create do nows that have problems that connect to the task that students will be working on that day. Today I want students to quickly review the measurement facts that they are expected to know on our state test. We check the answers together. I stress to students that they need focus on memorizing these facts.

*expand content*

#### Conversion Review

*5 min*

I tell students to get out their foldables from the previous lesson. They can use it as a resource to complete the conversions. As students work, I walk around to monitor student progress. I am looking to see that students are using the correct measurement fact as well as setting up and labeling their ratios. **Students are engaging in MP5: Use appropriate tools strategically.**

We come back together and I ask students to share out their strategies and answers to problem 4. I want students to realize that 7,000 pounds is equal to 3 ½ tons.

*expand content*

#### Comparing Measurements

*5 min*

I have a volunteer read the information and the question. Students participate in a Think Pair Share. Students are engaging in **MP2: Reason abstractly and quantitatively **and** MP3: Construct viable arguments and critique the reasoning of others**. I call on students to share their thinking. I ask students how that fact can help us determine whether Kate or Alexa is taller. I want students to realize that if 1 inch is equivalent to 2.54 centimeters, we can use that fact to convert other amounts. We set up the ratios together and determine which girl is taller.

*expand content*

#### Practice

*10 min*

Students work in partners on the problems. I walk around and monitor student progress. My goal is that the students complete problem 1. If they complete problem 1 successfully, they will move on to problem 2. A common mistake is to incorrectly set up or label the ratios. I do not teach students to multiply when changing a “smaller” unit to a “larger” unit, or vice versa. I believe that this short cut does not help students; rather it is one more procedure that they are likely to mix up or forget. By using ratios, I believe students are able to understand that converting measurements is just creating equivalent ratios.

If students are struggling, I may ask one or more of the following questions:

- What units are involved in the problem?
- What are you trying to find?
- How can you use the information to create ratios?
- What operation are you going to use to create equivalent ratios?

With a few minutes left, I call on students to share their thinking to problem 1. I call on students to share if they agree or disagree and why. Students are engaging in **MP3: Construct viable arguments and critique the reasoning of others**.

*expand content*

#### Dr. Evil and Mini-Me

*20 min*

We watch the first video clip. http://robertkaplinsky.com/work/mini-me/#prettyPhoto I ask students, “What is the ratio, in inches, of Mini-Me’s height to Dr. Evil’s height?” I explain to students that they will be working with their partner on this task. There is information on this page and the next page that will help you. I remind students that they can look back at their practice problems to get ideas.

As students work, I walk around and monitor student progress and behavior. Students are engaging in MP1: Make sense of problems and persevere in solving them and MP2: Reason abstractly and quantitatively.

If students struggle, I may ask one of the following questions:

- What are you trying to figure out?
- What do you know?
- What extra information do you need?
- How does this problem relate to the practice problems we did? How is it different?

If students successfully answer the question, I may ask one of the following questions:

- How did you find your ratio?
- What does your ratio actually mean?
- Challenge Questions

We come back together for the last 5 minutes. Students share out their ratios and how they got them. Then we watch the second video clip. I ask students, “Why is your ratio different? Which ratio is more reasonable?” Students are engaging in **MP2: Reason abstractly and quantitatively**. I want students to realize that if the ratio of Mini-Me to Dr. Evil was really 1/8, then for every 1 inch of Mini-Me’s height, Dr. Evil would have 8 inches of height. Just by looking, we can see that Dr. Evil isn’t 8 times taller than Mini-Me.

*expand content*

#### Closure and Ticket to Go

*7 min*

I ask students why they would need to convert units from one system to another. I pass out the **Ticket to Go **and the **HW Converting Measurements Using Ratios Day 2.**

*expand content*

##### Similar Lessons

Environment: Urban

###### Finding Equivalent Ratios

*Favorites(3)*

*Resources(11)*

Environment: Urban

Environment: Urban

- UNIT 1: Intro to 6th Grade Math & Number Characteristics
- UNIT 2: The College Project - Working with Decimals
- UNIT 3: Integers and Rational Numbers
- UNIT 4: Fraction Operations
- UNIT 5: Proportional Reasoning: Ratios and Rates
- UNIT 6: Expressions, Equations, & Inequalities
- UNIT 7: Geometry
- UNIT 8: Geometry
- UNIT 9: Statistics
- UNIT 10: Review Unit

- LESSON 1: Nana's Chocolate Milk
- LESSON 2: Introduction to Ratios
- LESSON 3: Extending and Comparing Ratios
- LESSON 4: Ratios with Thinking Blocks
- LESSON 5: Working with Percents
- LESSON 6: Converting Measurements Using Ratios
- LESSON 7: Converting Measurements Using Ratios Day 2
- LESSON 8: Show What you Know About Ratios
- LESSON 9: Introduction to Rates
- LESSON 10: Heart Rate
- LESSON 11: Calculating Speed Day 1
- LESSON 12: Calculating Speed Day 2
- LESSON 13: Comparing Rates
- LESSON 14: Calculating Unit Rates
- LESSON 15: The State Fair
- LESSON 16: Better Deal Stations
- LESSON 17: Show what you know about rates
- LESSON 18: Finals Week Day 1
- LESSON 19: Finals Week Day 2
- LESSON 20: Unit 5 Review Stations
- LESSON 21: Unit 5 Test