##### Teaching Phase: How will the teacher present the concept or skill to students?

**Warm-Up (5 minutes)**

The goal of the warm up is to get students thinking about outcomes and possible ways to test their ideas.

As students come into the classroom, the warm-up will be on the board. "Predict what happens to heart rate after exercise. What are some ways we could test your hypothesis?"

Once students have had the opportunity to formulate their own ideas, engage the class in a discussion. Try to get the students to be more specific. For example, if a student says the heart rate will go up, ask them if they have an idea of how much. Probing questions helps students develop their ideas for testing the theory.

As students share their brainstormed ideas for testing the hypotheses they have created, the teacher can list ideas on the board. If no one comes up with testing heart rates before and after exercise, the teacher can suggest it and explain that they will be doing this today in class.

Ask students if it is enough just to have one piece of data to determine what happens to heart rate? Explain that the entire class will test their heart rates so that we can analyze the results.

**Gathering Data (10 Minutes)**

Ask students what they will need in order to find and gather this data. Possible responses may include stopwatches, a chart, knowing how to feel a pulse. Address any concerns, and provide stopwatches. You may choose to allow students to use their phones as stopwatches or utilize the classroom clock to measure the elapsed time. Another option is to have all students count their resting pulse at the same time, run in place at the same time, and measure their new heart rate at the same time.

Students should be split into pairs. The teacher can make the determination before class, assign numbers, let the students choose, or use numerous other strategies for finding partners.

First, students are going to measure their resting heart rate by counting their pulse while running the stopwatch for one minute. One student can count their pulse while the other student watches the time. Students should use a stopwatch to ensure they are accurate in their measurements.

Students should record their data on the given worksheet.

Next, the same student whose resting heart rate was measured will run or jog in place for one minute. Immediately after, they would measure the same student's heart rate now that they have exercised. Just as before, one student watches the time for one minute as the other student counts their pulse for one minute.

The same process is to be repeated so that the student whose heart rate has not been measured gets his or her resting heart rate measured, then exercises, then gets his or her heart rate measured again.

As students finish recording their data, they are to bring their results to the front board. This data can be organized in a variety of ways. For example, create a table with column titles: student name, resting heart rate, heart rate after exercise.

**Create Box Plots (15 Minutes)**

Ask students for different ways to display the data graphically. Discuss the benefits and deficits in using histograms, box plots, scatterplots, etc. Ask students "What type of information would be useful in order to compare resting heart rates to heart rates after exercising?" Students may come up with answers like mean, median, range, etc.

If you haven't already, discuss the value of creating box plots to compare the data visually. For example, you can see differences in the median and range, as well as compare the different quartiles.

In their pairs, students are to use the data to complete a double box plot on the given worksheet. One box plot will have the resting heart rate data, while the other will have the heart rates after exercise. Ensure that students label their box plots and use appropriate intervals on their axes.

**Analyze the Display (10 Minutes)**

In pairs, students will answer the questions on the worksheet regarding their box plots.

After students have had the opportunity to answer the questions on their own, discuss them as a whole group.

##### Formative Assessment

The teacher has many opportunities to assess student progress throughout the lesson.

1. As students are measuring each other's heart rates, the teacher can ensure that students understand displays that can be made using this data.

The teacher may ask questions like:

- What kind of information do we want to know about our data? (Students may answer: median, range, slowest heart rate, etc.)
- What kinds of displays would be useful in attaining this information? (Students may answer: box plots, histograms, scatter plots, etc.)
- What information can we get by looking at a box plot? (Students may answer: median, least number, greatest number, quartiles, range)

2. As students create their data displays, the teacher can ensure that the students understand the mechanics required to develop their displays.

The teacher may ask questions like:

- What pieces of information do we need to create a box plot? (Students may answer: 5 number summary, least number, greatest number, median, lower quartile, upper quartile)
- How can you find the median of a set of data? (Students may answer: Order the numbers from least to greatest and then find the middle value.)
- How can you find the median in a set of data with an even number of values (Students may answer: Find the two middle values and calculate the average.)
- How can you find the upper and lower quartiles? (Students may answer: Find the median of the numbers below the median and the median of the numbers above the median.)
- What would be appropriate titles for your box plots? (Students may answer: Resting Heart Rates, Heart Rates after Exercise, etc.)
- What factors determine the numbers/intervals on your number line? (Students may answer: the range of the data, the least number, the greatest number, etc.)

3. As students answer questions about their displays during guided and independent practice, teachers can inquire as to the understanding of each concept.

Teacher may ask questions like:

- What do you notice about the way your plots are spread out? What does that tell you about the data? (Students may answer: The resting heart rates are much closer together, that may mean that exercise affects students much differently.)

4. The guided practice worksheet is a formative assessment for students, as well. Possible answers are included on the answer key.