The orange you glad...? activity is a fun, yummy, and a little messy activity. Students will use an orange to investigate and develop the formula for the surface area of a sphere.
Here is the task/ handout.
Here is the lesson plan.
After working with the surface area, we moved on to investigate what the volume of a sphere is. We found a really neat video to explain the formula. We stopped the video along the video to make sure that the students were understanding the video and to ask them questions to see if they could predict the next step.
Here is the lesson plan including the link to the video and the questions.
After the video was over, we gave them some practice problems that could be completed in class or for homework. These problems include going from volume to surface area and investigating the effect of changing the radius (ie doubling, tripling, etc) on the surface area and volume of a sphere.