how do you make a pop up paper cube with an elastic band?

Answer 1

If one has a cube of paper, and make a cut along the diagonals of two opposite square faces, the cuts being parallel, it's possible to then fold the cube flat by pushing the opposite edges of the cube, the edges which connects the ends of the diagonal cuts. Some folds will be necessary on the faces with diagonals cut. If a straight rubber band is stretched and attached inside of the cube so that one end is at the vertex where one diagonal cut ends, and the other end is at the vertex where the other diagonal cut ends OPPOSITE of the first, this will cause the folded cube to spring back up as a cube. it can be folded by force, and will snap up together again as a cube when released.