Math Strand
Lub Dub, Lub Dub
Lesson Overview:
A doctor uses a stethoscope to listen to your heart. In this activity, pairs of students use cardboard tubes to listen for their partner's heartbeat. Children are often fascinated when they first hear the lubdub sound the heart makes. This lesson is an opportunity for students to observe heartbeats at rest and after exercise, and to work with math problems related to their observations.
Connection to the Core Lesson:
The core lesson (My Healthy Heart Booklet) introduces many concepts about the heart that students record and illustrate in a My Healthy Heart Booklet. This lesson extends on the relationship between the heart rate and physical activity by integrating more mathematical calculations, including making estimates.

Content Standards Addressed:
Common Core State Standards
National Standards
Learning Objectives:
After completing the lesson, students will:
 Count with understanding and recognize "how many" in sets of objects.
 Connect number words and numerals to the quantities they represent, using various physical models and representations.
 Understand various meanings of addition and subtraction of whole numbers and the relationship between the two operations.
 Understand the effects of adding and subtracting whole numbers.
Materials Needed:
 Enough cardboard tubes (from empty paper towel rolls) for every two students.
 Copies of The Beat Goes On worksheet.


Background:
Should students start asking some specific questions about the heart and heart functions, it is a good idea to refresh yourself  as the teacher/leader  on its basics:
The heart has four different bloodfilled areas, called chambers. The two chambers on the top of the heart are called the atria. The atria receive the blood returning to the heart from the body and lungs. The two chambers on the bottom portion of the heart are the ventricles. They serve to get the blood out to the body and lungs. Valves in the heart help to keep the blood going in the right direction. The mitral and tricuspid valves allow blood to flow from the atria to the ventricles. The aortic and pulmonary valves control the flow of blood leaving the heart. The valves open to let blood move ahead, but then close quickly to keep blood from flowing backward.
Suggested Lesson Steps:
1. Pass out copies of The Beat Goes On worksheet. Ask students to estimate or guess how many times their hearts beat in one minute and write down the number on their worksheets. Then, have some students share their estimates aloud. (Students may remember from the core lesson how many times their hearts beat, and that's OK.) Students may ask if you mean at rest or during exercise. Applaud that thinking and ask a student to explain the difference and then accept estimates for number of heartbeats at rest and the number during exercise. 
2. Let students know that they are going to see how close their estimates or guesses were. Have students pair up and pass out the cardboard tubes. Instruct students to take turns listening for their partner's heartbeat by placing the cardboard tube over the partner's heart. Students should count the number of beats per 30 seconds. (If this is beyond their abilities, take your own pulse or one student's pulse, and report the count to the whole class.) Add this number together twice to find out how many times the person's heart beats in a minute. Students should answer the other questions on the worksheet related to heartbeats at rest. All involve addition or subtraction.
3. If you did not talk about differences between heartbeats at rest and heartbeats during exercise in Step 1, ask students if their hearts will beat more in a minute, less in a minute or about the same if they run in place or jump rope for a minute. Give them an opportunity to try to explain their choices. Help them understand that the heart has to work harder when exercising, so it must beat more often. Then, have students estimate the number of heartbeats they will have in a minute immediately after exercising. 

4. Have one partner run in place or jump rope for 30 seconds, then listen again for 30 seconds, counting the number of heartbeats. They should then alternate. After both partners have exercised for 30 seconds, they should take turns exercising for one minute and recording the number of heartbeats. Again, they should answer the questions on their worksheets.
5. Ask students to come up with one other activity and math problem involving counting heartbeats. They should add this to their worksheet.
Followup Discussion:
The heart beats faster after the exercise in order to pump more blood (oxygen) to the working muscles. Why is this important?
Academic Extensions/Modifications:
There are numerous ways to adapt and expand this lesson to create appropriate math problems. In some cases, you should discard the worksheet and simply have students count heartbeats.
If students are struggling when trying to count the number of heartbeats, have them clap out the number instead.
To add an extra challenge, expand on Step 5 and have students create multiple problems and then combine them, challenging all students to complete the problems conceived by students.
Study more about the heart  complete diagrams, trace the path of blood through the heart and lungs, and read about the heart.
Assessment Criteria:
Class participation.
Successful completion of the worksheet.
