Bicycle Tire Revolution
Lesson 4 of 10
Objective: SWBAT create ratios comparing two measurements and use measurements to create unit rates.
When the students come into the room, they will need to complete the Entrance Ticket prompt that is written on the board: Thinking back to the Situation Room lab with the two balls we rolled, is there a way to determine which ball will roll farther if the balls have an equal rate of speed but different diameters? If so, explain how to determine which ball will go farther? If there is no difference in distance, explain how you determined that answer (MP3).
The goal of the entrance ticket is to start the class off with students thinking about how unit rates are determined. This time is also a good time to find out if students don’t yet have an understanding of what the unit rate is and how to find it. If they don’t, intervention may be necessary before taking students to the middle of the lesson.
After the whole class discussion on the differences in distance that the balls may travel, the class will move into an individual activity. I will give them a worksheet on bicycle tire revolutions. Students will answer the questions on the sheet. When the allotted amount of time has passed, each student will work with a partner to improve their answers. The idea behind this part of the activity is to allow students to explain and justify their work. On the board will be questions that each student needs to answer while working with their partner to support and/or improve their answers.
- How did you determine your answer?
- Does your work use specific steps to find the answer?
- Looking at your partner’s paper can you:
- Identify the unit rate?
- Determine if the unit rate is correct?
As students answer questions about their own answers and the answers that their partners found, I will be able to walk around and ask those questions myself. If there is confusion, I can help clear it up with individuals and partners. I can ask questions such as, “Will that strategy work every time?” and “Is there another way to find it?” I want to see if students are using repeated reasoning to determine their answers or if it is more luck of the draw. The goal is for students to know and to understand how to determine and use a unit rate to solve problems. I want to make sure they know how to do that. After the partner activity, we will review the sheet as a whole class discussion. I want to talk about the problems on the sheet as a group to ensure that everybody has an understanding of how to find the rates and what to do with the comparison of those ratios.
As an exit ticket, I will ask students to revisit the entrance ticket question. This will be a quick formative assessment to show me what students understand and what they may still be having trouble with after the lesson. If students are able to provide a complete explanation for their answer, they are ready to move forward. If the explanation given doesn’t answer the question correctly or if they are unable to provide an answer, then I have a starting point for intervention.
Is there a way to determine which ball will roll farther if the balls have an equal rate of speed but different diameters? If so, explain how to determine which ball will go farther? If there is no difference in distance, explain how you determined that answer.