What You Do:
1. Tape the long edges of the mirrors together so that they form a pyramid shape, with the reflecting sides of the mirrors all facing inward.
2. Next, cut out a triangle of thin cardboard to fit one end of the kaleidoscope and tape it on. Use a sharp pencil to poke a hole in the center of the cardboard, to serve as a peephole.
3. Cut two triangles of a transparent substance, like a plastic overhead transparency, to fit the other end; tape up two of the edges to form a three-sided envelope, and put candy sprinkles and/or bits of colored paper inside. Tape the third side closed, then use tape to attach the envelope to the end of the kaleidoscope.
4. Now, look through the end that has the peephole and aim the kaleidoscope at a light source. The colored objects on the other end will reflect off of the mirrors into star-shaped patterns.
You can also study reflection using two small square glass mirrors taped together on one side. Stand them upright and spread them apart like an open book, so that a small object can be placed between them without touching on either side. How many reflections do you see? Now, lay a pencil in front of the mirrors so that it touches on each side. How many pencils are reflected? Experiment with moving the mirrors closer to and further from each other; how does the number of reflected objects change in relation to the angle of the mirrors?