## What's the Beat?

In this activity, students use the average adult's number of heartbeats per minute to predict how many times the heart would beat during various lengths of time. The students also draw conclusions on the basis of information about the human heart rate and that of other animals.

Begin the class with a discussion and review of the previous lesson. Students should recall the salient points of that lesson. Ask students to predict who would have a higher heart rate: a child or an adult. Discuss students' responses.

Next, ask students to identify factors which may impact the heart rate of an adult. Students might suggest the following:

- Diet
- Age
- Daily exercise
- Weight
- Other genetic factors

Distribute a copy of the What's the Beat? Activity Sheet to each student.

What's the Beat? Activity Sheet

Have the students read the introductory statement, which gives
the number of heartbeats per minute for the average adult at rest.
Remind students that this is only an *average* and that people's heart rates may vary

Have the students determine, using the average adult heart rate, the number of heartbeats for each length of time listed in question 1. Students should use be prepared to discuss how they arrived at their answers.

A range of answers is acceptable, even encouraged, depending on how the students solved the problems. For example, some students may find the number of heartbeats in a day and then multiply by 28, 29, 30, or 31. To get the number of heartbeats in a month. Others may find the number of heartbeats in a week and multiply by 4 to obtain the number of heartbeats in a month. Some students may use 52 weeks, and others, 365 days, in determining the number of heartbeats in a year. The ranges in the responses should be discussed.

Using the answers in question 1, have the students complete questions 2‑4 and discuss their responses.

Next, have the students complete question 5. Discuss the students' responses and conclusions.

An answer key is provided for you to check student responses on the activity sheet.

### Reference

Lisa M. Passarello and Francis (Skip) Fennell, "IDEAS: Every Beat of Your Heart." The Arithmetic Teacher, 39, 1 (February 1992) 32-39.

**Extensions**

- Students can ask an adult to measure their own heart rate at rest. Students can use this information to answer questions 1, 2, and 3 on the What's the Beat? Activity Sheet for their family member. This will make the data more authentic and help students compare their adult family member's heart rate to the average.
- Using the heart rate data collected in
**1**, create a class line plot, stem-and-leaf plot, or other appropriate graph, to represent the class data. - Determine the class mean, median, mode, and range for adult family member heart rate data.

### Every Beat Of Your Heart

### Learning Objectives

Students will:

- Determine how many times the adult heart beats during specified lengths of time.
- Predict how many times the adult heart would beat during other lengths of time.
- Draw conclusions on the basis of information about the human heart rate and that of other animals.

### NCTM Standards and Expectations

- Develop fluency in adding, subtracting, multiplying, and dividing whole numbers.

- Propose and justify conclusions and predictions that are based on data and design studies to further investigate the conclusions or predictions.