Tetra means four and this model folds into a 4-sided shape (a
square of course). It's called a 'flexagon' because it's flexible,
so we bend it and move it about, but it always comes back into a
square.
First you will need to draw the six squares or print off this page, and cut around the shape. If you can, use thin cardboard. (You will need to 'score' the folding lines by tracing over them heavily with a pen and using a ruler).
Write the numbers 1, 2 and 3 on the front as shown. Now turn it over (not upside down though) and write the numbers on the back as shown below.
Turn to the front again, then fold the two 1's on the top flap BEHIND, as shown below.
Now fold the 3 that's sticking out, across and tape it to the 2 above it. (See below). You'll know if you've done the folding correctly because all the 2's will be on the front, and all the 1's will be on the back. But where have the 3's gone? To make them appear, gently lift the loose flaps on the front (see where the dots are on the picture below), and sort of turn it inside out.
It will be a bit stiff to start with, but it's fun once you get the idea. If you've used paper, it might tear - but now you know how to make it, you can make a new one out of cardboard. You might like to use three colours instead of the numbers.
First you will need to draw the six squares or print off this page, and cut around the shape. If you can, use thin cardboard. (You will need to 'score' the folding lines by tracing over them heavily with a pen and using a ruler).
Image
Write the numbers 1, 2 and 3 on the front as shown. Now turn it over (not upside down though) and write the numbers on the back as shown below.
Image
Image
Turn to the front again, then fold the two 1's on the top flap BEHIND, as shown below.
Image
Image
Now fold the 3 that's sticking out, across and tape it to the 2 above it. (See below). You'll know if you've done the folding correctly because all the 2's will be on the front, and all the 1's will be on the back. But where have the 3's gone? To make them appear, gently lift the loose flaps on the front (see where the dots are on the picture below), and sort of turn it inside out.
Image
Image
It will be a bit stiff to start with, but it's fun once you get the idea. If you've used paper, it might tear - but now you know how to make it, you can make a new one out of cardboard. You might like to use three colours instead of the numbers.