Spinners for Probability
Spinners are visual aids with a segmented face and moving pointer used for demonstrating probabilities. Unlike static illustrations, such as those used when teaching fractions, spinners enable active participation in probability experiments. Make spinners with your students at the beginning of your probability unit to illustrate the similarities between fractions and probabilities. Base practice problems and worksheets off of the spinner to clarify the connection. For example, if you have a spinner with four unique quadrants, ask students to calculate the probability of landing on a particular color. In addition to being able to count the sections and arrive at the answer (1/4), pupils can run an experiment to test the accuracy of their response.
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Large Spinner
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Large spinners can be used for in-class assignments and group work. There is no limit to the size of your spinner; however, spinners larger than 6 inches require the use of thicker materials. Make the base of a spinner by cutting a 6-inch round out of a sturdy piece of cardboard or thick card stock. Cut out a 2- to 3-inch arrow from the same material. Punch holes in the center of the cardboard and the base of the arrow and fasten the arrow to the cardboard with a paper fastener. Flick the arrow to ensure that it moves freely. Divide the base into four quadrants and color each quadrant differently.
Pocket Spinner
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Select a metal bottle cap with a flat surface. Lightly sand the cap to break the protective coating and improve paint adhesion. Color half of the cap red and half blue. Protect the paint with acrylic sealer. Use an awl to poke a hole into the center of the cap. Start the hole from the interior of the cap to prevent the metal from bending. Insert a wire into the hole and bend it to form a "U" such that the parallel lengths of the wire are on top of and inside of the cap. Hold the cap by the sides and flick the wire length to spin.
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Repair
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Make miniature spinners in class to increase interest in probability and encourage students to use visual aids to clarify their homework. Clear packing tape can be used to repair surface tears. Apply tape to the entire length of the base to discourage further damage and enable the spinner to move freely. Repair spinners by undoing the paper fastener and separating the arrow from the cardboard base. Make a new arrow out of a similar material and replace the original using a fresh paper fastener.
Alternatives
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Any object with flat, distinctive faces can serve as an alternative to a spinner, such as coins, wooden blocks or dice. The key to selecting an item is to choose an object that has an equal chance of landing on each sides. Shaped objects, such as metal bottle caps and plastic container lids, are more likely to land on one side due to air current, as are dented coins, weighted dice and objects on which one side is heavily carved.
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References
- Photo Credit Jupiterimages/Photos.com/Getty Images
