Lesson 7
Surface Area and Absorption
HBS, pp. 50 - 59
Reference: SI, pp.
Name/ Per.__________________________
Lesson Objectives:
1. Calculate the surface area of a cube and a rectangular solid.
2. Explore how to increase the surface area of a cube while working within constraints.
3. Build a model of a cross-section of the small intestine.
4. Calculate and compare the surface areas of folded and unfolded strips of tickets.
5. Discuss the relationship between surface area and absorption in the small intestine.
6. Read about what happened to undigested food and water in the large intestine.
Pre-Inquiry “Getting Started “Questions with the teacher
1. How would you calculate the surface area of your desk?
Length X width = ____ 2 (one side)
2. How would you calculate the surface area of one side of a cube that has the dimension of
4 cm X 4 cm X 4cm?
4 cm X 4 cm = 16 cm 2 (one side)
3. How would you calculate the total surface area of that cube?
6 (sides) X 16 cm 2 = 96 cm 2
4. How are a cube and a rectangle different?
The sides of a cube are the same dimension. The sides of a
rectangle are the different sizes.
5. Calculate the total surface area of the 5 cm X 5cm X 10 cm rectangle.
5 cm X 5 cm = 25 cm2 X 2 sides = 50 cm2
5 cm X 10cm = 50 cm2 X 4 sides = 200 cm2
Total surface areas = 250
Inquiry 7.1 See attached sheet for procedures. Answer Inquiry 7.1 questions on this paper.
4. How would you define the”surface area” of the clay?
5. Diagram your method. Defend your answer mathematically by calculating the new surface areas
and comparing it with the original area.
Inquiry 7.2 See attached sheet for procedures. Answer Inquiry 7.2 questions on this paper.
5. Calculate the surface area of the inside of the folded strips of tickets.
6. Compare the surface area of the folded and unfolded tickets and express the relationship between
the surface areas as ratio (e.g., 5-to- 1)
Post-Inquiry “Reflections” Questions
Revise all your answers, use and circle the following vocabulary words:.)
Which would dissolve faster in a cup of hot water, a sugar cube or a teaspoon of sugar (assuming
equal weights)? Defend your answer.
The grain of sand has more surface area than a cube of sugar, As a
result, the teaspoon of sugar should dissolve more quickly.
What might a human like if he/she had no folds in the small intestine?
To absorb all the nutrients needed, the small intestine would have to
be much larger than it is now is and the human abdomen would have
to be enormous.
HOMEWORK

Use Student Sheet 7.1 to study for the upcoming Test.