I was asked more about the engineering challenge I gave my 5th grade when I was teaching my cake lesson. Here's what I did. The red triangle above was a pre-cut 1/8 of a circle. This was the key to making all the cake slices fit together. I gave the kids recycled tagboard. and gave them 20 minutes and the directions above. They were able to work in groups. I let them struggle for an about 8-10 minutes developing their own ideas of a solution. Then I place out an example. Kids were asked to look but not touch to get hints of how to create this shape. You will see this in the video below.
For my 5th grade I choose to then give them steps to draw out the final cakes on the cardboard. This worked well because all students felt successful. The uniformed shape was then decorated as shown on previous post.
The lesson continues in other classes. Here is a post from @. She writes...
@MiniMatisse Done! 8th-grade w/use Pythagorean to solve triangle equation 4 base! Math dept. on board! Weee!
That is why I post lessons. It's great to collaborate with others from all over the world. She also shares her thought and projects on both her website and twitter.