Give each child a paper towel tube to decorate. Allow the preschoolers to use crayons or markers to adorn the outside of their tube however they wish. Older preschoolers may enjoy using paint or stickers in addition to crayons and markers.
Fold your reflective paper into a triangular prism and place it inside the paper towel tube once each child has finished decorating. Use mirror board paper, available at craft stores, and wrap the paper with the shiny, silver side. An alternative would be to use a clear plastic report cover for the triangular prism. Tape the edges of your paper together so it does not fall apart after it is inserted into the tube.
Cut a circle from construction paper that is just larger than the end of the roll and punch a hole in the middle that is large enough for the child to look through. Help each child tape the construction paper circle to one end of the tube.
Place a piece of plastic wrap on the other end of the tube, making a small indentation so that it dips down into the paper towel tube slightly.
Have the child place small, decorative objects on the plastic wrap. Invite them to use small beads, paper scraps, sequins or other small, interesting items in their kaleidoscope and monitor your preschoolers so they do not add too many objects, making it difficult for the items to move once the kaleidoscope is finished.
Cover the plastic wrap pouch with a piece of wax paper and place a rubber band over it to contain the small objects. Ensure that the small items are tightly secured inside the pouch so that none of them are lost when the children use their kaleidoscopes.
Show children how to change the image that they are looking at by rotating the kaleidoscopes while they look through the hole they cut in the construction paper.