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# Making a moebius strip

• paper
• scissors
• a pencil

## What to do

A moebius strip only has one edge and one side.

You'll create a moebius strip from a strip of paper with a half turn in it and the two ends joined to make a loop.

1. Cut a strip of paper 30 cm long by 5 cm wide (or something like these proportions - it doesn’t need to be exact!).
2. Join the ends to make a hoop, but give the strip a half twist before you tape it together.
3. Draw a line along the centre of the strip.
4. Cut the strip in half along its length.

How much bigger is your loop than the one you started with? How much bigger is the loop if you cut the strip into thirds or quarters? Can you draw on only one side of a Moebius strip?

## What's happening

Moebius strips are often used as belts in machinery because they last longer - they wear out both ‘sides’ at once.

This useful strip is part of a branch of mathematics called topology. Topology can be hard to explain, because in it straight lines or edges aren’t important, and a circle is considered to be the same as a square. In topology, one is just a distorted or deformed version of the other!

This loopy structure was invented by a German mathematician named August Moebius. Its amazing properties arise from the fact that this strip of paper has only one edge and one side!