I have to give credit to estimation180 for this one. If you haven’t been to this fabulous website you have to go there immediately! I was totally surprised at how my students figured this one out. It amazed me how close some of them came to the real answer with some very simple methods. Also there were some extremely complex methods, I wish i had taken a picture of one of them a student did on the white board. It was awesome!

Remember to use these you should do A three part lesson Ala Dan Meyer

Ask the students: what’s the question?

Get them all to guess and record their guesses, (i like to use post it notes)

then have them see if they can improve their guess by calculating the real answer.

Then, have them explain it their answer in writing.

by the way the real answer calculated using photoshop is 423.9 square units.