Distribute a copy of the Heartifacts Activity Sheet to each student.
Have the students read and discuss the facts about the heart, as stated at the top of the activity sheet. They will use these facts to answer questions 1‑4 on the activity sheet. Discuss students' responses and how they arrived at their
answers. Responses should fall in the range of answers given at the conclusion of the Instructional Plan. For question 2, discuss ways to use mental computation to determine one-half of 1 percent of a
person's weight. Emphasize that the students should determine how they arrive at their estimate for problem 3.
Finally, have students use the facts to create an original problem of their own. They should solve the problem and then have a friend try to solve it.
Answers to the Activity Sheet:
- Seventy beats per minute equals 100,800 times a day, or 36,288,000 times a year; 100 beats per minute equals 144,000 times a day, or 52,560,000 times a year. Both responses are based on a 365-day year.
- Answers will vary according to students' weight.
- About 7,500 quarts each day.
Estimate: The number of quarts pumped per hour is 5 × 60 = 30,024 to close to 25 and 25 × 3 = 75, so 25 × 300 = 7,500. Or, about 6,500 to 7,300 liters each day. Students might round the number of liters pumped per hour from 4.7 to 5 and the number of hours in a day to 25, so 5 × 60 = 300, and 300 × 25 = 7,500. Since two numbers, 4.7 and 24, were rounded up, the 7,500 estimate should be lowered, say, to 6,500 to 7,300.
- After exercise, the heart would beat 112 ‑ 122 times in one minute based on 70 beats per minute at rest or 160 ‑ 175 times in one minute based on 100 beats per minute at rest.
- Answers will vary.
