Teachers need lots of tools in their arsenal when it comes to teaching any subject, especially math. The use of a spinner is a great way to introduce math concepts related to probability. The Classroom Spinners app provides teachers with six different types of spinners that can be configured to have sections with color or no color. The sections can be labelled with numbers or letter. The sections can also be unlabelled.

Tapping the info button brings up a screen explaining the various functions of the app.

The Classroom Spinners screen shown below is configured to have six sections. Each section has a different color and the sections are labelled with letters. Many different investigations of probability theory can be explored using this setup.

For example, here are a few questions to ask the students:

- What is the probability of landing on a vowel?
- What is the probability of landing on A,B, or C?
- If the last five spins were A,A,C,A,A, what is the probability of the next spin being the letter A?
- What is the probability of getting an B on the first spin and E on the second?
- If you spin 10 times about how many times would you expect the letter D to occur?

Tapping the sigma icon will display a table of the Experimental Outcomes:

In this experiment the letter C was randomly selected 4 times. The Theoretical Probability for any given letter is 16.7%. What do you think will happen to the Experimental Outcome for the letter C if 90 more spins are performed? Theoretically, how many times will C occur if the experiment is run 1,000 times?

Classroom Spinners is a useful tool for teachers to have in their tool bag. Check it out and let me know what you think.