6th Grade Math Lesson Plan: Surface Area II

Objective: Students will be able to identify the proper equation for finding surface area of a cube, a rectangular prism and a pyramid with a square base.

Lesson Opening

1. Ask your students to remind you of the things you learned yesterday about surface area and volume. The key points to hit are: the definitions SA and V, squared units vs. cubed units and how you can find the SA of a cube by finding the area of one side and multiplying by six.

Guided Practice

1. Say, "Yesterday, you may have thought that finding the surface area was easy. After all, all you had to do was find the surface area of one side, and you were done. Things aren't going to be nearly as easy today. You may not have to measure all six sides, but you will have to measure more than one."

1. Ask the children to come up with an equation for finding the surface area of a cube. The correct equation is SA = 6 x l x w. Explain that by the end of the day, they will have come up with equations for a rectangular prism and a pyramid with a square base.

1. If there is time, have the children do a quick worksheet where you give them the length, width and height of a cube (all the same, of course) and they solve for SA.

Independent Practice

1. Have the class complete an area worksheet and go over the answers with the class. Ask if they have any questions about finding the area of two dimensional objects.

1. Pass out the cut-out for creating a rectangular prism and a pyramid. Have the children cut and paste them individually (glue sticks work best) or have them work with a partner if you don't have enough materials.

1. Ask the children if they have any suggestions as for how to find the surface area. Explain that while finding the surface area isn't as easy as finding the surface area of a cube, there are still short cuts that can be taken.

1. As proof that they have completed the assignment, have the children write the surface area of the cube on one of the sides and turn it in.

1. Ask the children to come up with two equations. For a rectangular prism, the equation is SA = 2 (l x w) + 2 (w x h) + 2 (l x h). For a pyramid, it is 4 (½ bh) + (l x w). The height is the height of the triangle side, and not of the pyramid.

Closing

1. Ask the children when in real life they would need to measure the surface area. One example: a cereal box maker needs to know surface area so he/she can figure out the manufacturing cost.