Investigate the surface area of a cereal box by looking at its net.
Objectives
To experiment with how to find the surface area of a composite solid.
To understand how nets relate to surface area.
Materials
Cereal box
Scissors
Ruler
Sharpie
Surface area of a cereal box
Procedure
Follow the steps below to find the surface area of your cereal box.
Take your cereal box and carefully unfold the top and bottom flaps.
Cut off any sides that are not necessary for making the box whole again. For example, the top of the box only needs one flap, not 4.
Cut the box along the edges so that you can lie the box down flat and it is still in one piece.
For each of the different shapes that make up the net of the cereal box, measure the side lengths, followed by calculating the areas and writing the results directly on the shapes.
Pay attention to the units you used for this.
Investigate
Consider the following questions once you have completed the procedure above.
1.
How many faces does the cereal box have?
2.
What is the surface area of the cereal box? What units is it in?
Discuss your responses to the previous questions with a classmate, then answer the questions below.
Discussion
1.
What real-life situations can you think of where calculating surface area of an object could be useful? Brainstorm at least 3 different situations.
2.
Compare your situations with a classmate. Did they think of one you didn’t?
Outcomes
6.G.A.4
Represent three-dimensional figures using nets made up of rectangles and triangles, and use the nets to find the surface area of these figures. Apply these techniques in the context of solving real-world and mathematical problems.
