Calculating Speed Day 1

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Objective

SWBAT: • Make conversions to determine my speed using different units • Use multiplication and division to calculate rates

Big Idea

What was your sprinting speed in miles per hour? Students use conversions and rates to calculate their speed.

Do Now

7 minutes

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 start thinking about what speed really means. 

I ask students, “What does it mean for Usain Bolt to run at a speed of 23 miles per hour?”  I want students to set up the rate, recognizing that “per hour” means their denominator needs to be 1 hour.  Just because he was traveling at a speed of 23 mph does not mean that he could maintain that speed for an hour.  

Setting Expectations

5 minutes

I tell students that today they will be working to figure out their sprinting and walking speeds.  I tell students to copy their data from the previous day’s packet.  I tell them that by the end they should know their speed in miles per hour.  I ask students what conversion facts they think they will need.  I copy them on the board and students put them in their packet to refer to later.

I tell students that this task is complex.  They have skills and strategies for working with rates and measurements and all of these skills will help them to work through the task.  

Part 1: What was your sprinting speed?

28 minutes

Notes:

  • Before this class, I use the data from the previous lesson’s TTG to Create Homogeneous Groups of 3-4 students.
  • Each group receives a Group Work RubricI use this data to give each student a citizenship grade for the day.
  • My goal is for students to at least complete the questions in part 1 today.  We will be working on extending this task during the next lesson, so students will have some time to work on part 2.

I tell students about the groups they are working in.  Students move into groups and begin working.  Each student has unique data, but they will be able to ask each other questions about how to change their rates and measurements.  I walk around to monitor student progress and behavior.  Students are engaging in MP1: Make sense of problems and persevere in solving them, MP2: Reason abstractly and quantitatively, MP5: Use appropriate tools strategically, and MP6: Attend to precision.

If students are struggling, I may ask the following questions:

  • How long did it take you to sprint 40 feet?  How can we figure out how many feet you traveled in 1 second?
  • How far did you travel in one second?  At this rate, how far would you travel in 2 seconds?  In 3 seconds?
  • How can you use what you have to create a rate showing how far you would travel in one minute?  What units do you have?  What units do you need to have in your answer?
  • If you know how far you travel in a minute, how far will you travel in one hour?
  • How far would you travel in one hour?  What units do you have?  What units do you need to have?

If students are struggling with the actual calculations, I have calculators for students to use.  If a student uses a calculator, I still require them to set up the rates and show the calculations he/she is making to get the answer.

If students need extension, I may ask them the following questions:

  • What if your walking speed is 1 meter per 1.5 seconds, what is your speed in feet per second?
  • How does your speed in mph compare to your estimate?
  • How long do you think you could keep up this speed?

If students successfully complete part 1, they move onto part 2.  I took away the scaffolding in part 2 so students need to complete multiple steps to answer the questions.  If they struggle, I have them look at their process in the part 1 problems as a reference.

 If students successfully complete part 2, they move on to the challenge questions.  If students ask me how many kilometers are in a mile, I will give them the conversion.  I want students to figure out on their own what information they need to know to complete the problem.

Closure and Ticket to Go

10 minutes

I ask students to share out how they found their speed in feet per second.  I have a student come up to the front to show and explain their thinking under the document camera.  I ask students to come up to show and explain their work for problem 3 and 4. Students are engaging with MP3: Construct viable arguments and critique the reasoning of others.  I ask students to show me with their hands if they have completed the problems in part 1. 

I ask students to share out what obstacles they encountered and whether/how they overcame them.  I remind students that they will be working on a task using this data in the next lesson. 

With a few minutes left, I pass out the Ticket to Go and the HW Calculating Speed Day 1.