Introduce the concept of probability by reading the book, "Ten Little Monkeys" by Annie Kubler. In the story, little monkeys repeatedly fall off the bed and bump their heads. As you are reading the story, pause frequently to ask questions such as, "How likely do you think it is that another monkey is going to fall off the bed?" or "What is the chance that the momma monkey will call the doctor after one of her babies bumps its head?" Upon finishing reading the story, inform your students that the chances of an event happening, like a monkey falling off the bed, is probability.
Write the key vocabulary words on the board that your students need to know for the study of probability. Include terms such as likely, unlikely, more likely, less likely, 50/50, certain and impossible. Discuss what each of the terms means and give examples. For example, it is certain the sun will be coming up tomorrow. An example of an event that is 50/50 would be flipping a coin. Ask students to give other examples. Correct their ideas when necessary.
Introduce the activity, "Rolls to Empty the Bowl." To do this activity, students will be paired up and given one die, 12 colored tiles, a bowl and pencil and paper to record their data. Students will roll the die and remove the number of tiles that corresponds to the number they rolled. Students continue rolling the die and removing tiles until they have removed all of the tiles from the bowl, then they should calculate the number of rolls it took to empty the bowl. Have them repeat the activity five times.
Come back together as a class and have the partners share the number of rolls it took to empty their bowls each time. Review the vocabulary terms from the beginning of the lesson and have students make observations about the class data using probability terms. For example, if the most common number of rolls to empty the bowl was three, a student could say that it is more likely to take three rolls to empty the bowl than six. Challenge the students to use the term impossible. Clarify any questions your students may have.