Mrs. Nelson came into our class to do a challenging "thinking" activity!
The Möbius strip or Möbius band is a surface with only one side and only one edge. It can be made using a strip of paper by gluing the two ends together with a half-twist. The twisting is possible in two directions; so there are two different (mirror-image) Möbius strips.
The Mobius strip is known for its unusual properties. A bug crawling along the center line of the loop would go around twice before coming back to its starting point. Cutting along the center line of the loop creates one longer band, not two. Cutting one third of the way in from the edge (and parallel to it) produces another amusing result.