Just for fun, ask your students to cut the largest hole that they can in a standard 8.5" x 11" piece of paper. (I usually give the kids a piece of scrap paper to try) Then, tell them that you will teach them how to cut a hole large enough for them to walk through! Give them this page and show them how.
1. Fold on dotted line (fold will end up on the back side to ensure that they cut through it).
2. Cut on solid lines--cut through both layers of paper on each line, through the fold and off the unfolded edge.
3. Walk through that hole!