To start you just need a sheet of copy paper (using color here to make it easier to see!).
Fold in half - "hamburger" style.
Fold in half again. This creates a crease down the middle to help students with the "shutter fold."
Fold in the sides to the center crease. At this point of the year, my students have made several shutter fold foldables, so this part is easy for them.
Each shutter now becomes the front of a house. Open it up and the top folds down to become the "roof."
Do the same to the other shutter. Students can now write 3 numbers on the roof and the facts on the front of the houses. I also had my students make arrays under the flaps to model the facts.
Once students know how to make the houses this can become a math station activity.