The Challenge: Crochet 2 möbius strips, of opposite chirality. Then sew their edges together to get your very own Klein bottle! (A Klein bottle has no obvious inside or outside.)
Materials Needed: Crochet or knitting skills, yarn.
Math concepts you could explore with this challenge: topology
Here’s some more about klein bottles:
Depending on how you use this activity, you may engage with different mathematical standards. I’ve listed possible connected math content above. Here are a few suggestions for how you might integrate the 8 mathematical practices. Feel free to add your own suggestions in the comments!
5.) Use appropriate tools strategically. Here, if you want to be able to make your own shy of a 3D printer or a glass blowing ability, you’ll need to be able to either sew together two möbius strips of fabric. The flexibility is necessary.
7.) Look for and make use of structure. Where is the inside? Where is the outside? How many openings does this thing have!?