From 3 weeks ago, here is the filing cabinet post-it activity. It was originally created by Andrew Stadel and available on the 101 Qs website here. I’ve made my own photo prompt for act 1 so that students can do the measuring on our classroom filing cabinet in act 2.

**Act 1**

**Act 2**

Each group was given 1 sheet of paper. Students got busy measuring the filing cabinet and their sheets of paper. They worked at their boards:

There was some confusion to start about how to “read” and thus use the formulas for surface area on their formula sheet. A few groups worked through the areas of each face instead of the formula. I did a little direct teaching about nets and they can be more intuitive to use than the formulas.

Most groups got answers around 60 sheets.

**Act 3**

After all my years of using this activity, I have yet to get a group interested enough to take the time to cover my filing cabinet with paper to get the actual real life answer to see how close their work is. They always seem content that their Math has found the answer. Perhaps I just need to do it myself one of these days.

The individual practice was 2 sets of exercises on Khan Academy:

Part 1 – Nets of polyhedra (quick)

Part 2 – Surface area using nets

All of my materials are available here.

– Laura Wheeler (Teacher @ Ridgemont High School, OCDSB; Ottawa, ON)