HOW MANY SIDES TO A PIECE OF PAPER

WHAT YOU NEED

11"x14" piece of paper
scissors
3 pieces of tape
marker

WHAT YOU DO

Fold the paper in half long ways. Fold it long ways again. Cut out 4 strips along the fold lines. Color one side of each strip.

Make a loop out of one strip and tape the ends together. The colored side should be on the inside of the loop. Make sure the tape completely covers the ends.

Form a second strip into a loop but twist it once before taping the ends. Make the third loop like this, too.

Pick up the first loop and look at it. How many sides does it have? ______ Trace your finger along the colored side of the paper. No matter how many times you go around, you stay on the colored side. You never get to the white side.

Now look at your second loop, one with a twist. Trace your finger along the colored side. Do you ever get to the white side? ___________________ How many sides would you say this figure, the Mobius Strip, has? ________

What do you think will happen if we cut the first loop in half along its length?

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Try it. What happens?

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Next, we're going to try to make two Mobius Strips by cutting one in half long ways. Do you think that we'll succeed? _______

Very carefully cut the strip in "half". What happens?

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Now if you trace your finger along the colored side do you get to the white side? _________________

Let's try cutting the Mobius Strip in "half" again. What do you think we'll get this time?

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Cut very carefully since the strip is very thin. What did you get?

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