As a class, determine the probability that the arrow will land on a certain color of the spinner. For instance, if the spinner has four colors, including red, the arrow has a 25 percent chance of landing on red. Instruct each student, at her own desk, to test this probability by spinning the arrow once. Ask the students who landed on red to raise their hands. Calculate the number of raised hands in relation to the entire class. Discuss with students why the percentage may be higher or lower than 25 percent, explaining that probability does not guarantee certain outcomes, but instead predicts likely outcomes.
Use an activity to teach that the results of experiments of probability tend to become more representative of probability the more times that they are repeated. Instruct students to pick a color on the spinner and to spin five times to record the percentage of times that the spinner landed on that color. Then instruct students to spin 10 times and then 20 times, recording the new percentages at each interval, based on the total number of spins. Students will likely find that the percentage becomes closer to the predicted probability the more times that they spin. However, emphasize to students that probability is not based on prior outcomes.
Complicate the process of calculating probability by showing students a spinner board with spaces that vary in color, shape and number. For instance, draw a spinner on the board that has 10 spaces which feature five different colors, 10 different numbers and three different shapes in which the number is inscribed. Position the arrow on top of a space. Challenge the students to determine the probability that the arrow will land on the color, number and shape indicated.
Invert the last activity to compel students to determine the circumstances of probability. Present a spinner board with many spaces that feature different colors, shapes and numbers and give the students a figure of probability (50 percent, for instance). Challenge students to creatively think of the outcomes that have a 50 percent chance of occurring. For instance, there is a 50 percent chance that the arrow will land on an even number or there is a 50 percent chance that the arrow will land on a primary color.