Early Math Counts

• Six jars or clear cups filled with different-colored marbles or colored manipulatives  
  •  A jar containing only blue marbles
  • A jar containing only green marbles
  • A jar containing three yellow marbles, one green marble and one blue marble
  • A jar containing only red marbles
  • A jar containing three green marbles, one yellow marble and one blue marble
  • A jar containing only orange marbles
    (You can also use pictures of gumball machines with different-colored gumballs. You will not need a lot of marbles or gumballs for the containers.)
• Three probability cards labeled: Certain, Possible, Impossible

Note: Small parts pose a choking hazard and are not appropriate for children age five or under. Be sure to choose lesson materials that meet safety requirements.

1. Give the children a working definition of probability—the chance that something is going to happen. Explain that today they are going to explore the concept of probability.
2. Explain that today they are going to each pick marbles from a jar and decide on the probability of picking a certain color.

1. Provide examples for each of the probability cards:

Using the jar containing only blue marbles, ask: “What is the probability that I will pick a blue marble? Is it certain that I will pick a blue marble? Is it possible that I might pick a blue marble? Or is it impossible to pick a blue marble? Since the marbles are all blue, it is certain that I will pick a blue marble.” Have a child pick a marble out of the jar and respond to the marble that he/she chooses. (Certain) Place the “Certain“ card in front of the jar.

Using the jar containing only orange marbles, ask: “What is the probability that I will pick a blue marble? Is it certain that I will pick a blue marble? Is it possible that I might pick a blue marble? Or is it impossible to pick a blue marble out of this jar of all orange marbles?” Again, have a child pick a marble out of the jar and respond to the marble that he/she chooses. (Impossible) Place the “Impossible” card in front of the jar.

Using the jar containing three green marbles, one yellow marble and one blue marble, ask: “What is the probability that I will pick out a green marble? Is it certain that I will pick out a green marble? Is it possible that I might pick out a green marble? Or is it impossible to pick out a green marble?” Have a child pick a marble out of the jar and respond to the marble that he/she chooses. (Possible) Explain that it is possible to pick out a green marble, but it is not certain because one could also pick out a yellow marble or a blue marble. Say: “The chances are higher that I will pick out a green marble, but they are not certain because there are other colored marbles in the jar.” Place the”Possible” card in front of the jar.

2. Pose questions to the children about each of the jars and the probability of picking certain colored marbles. Have the children take turns answering the questions and placing the probability cards in front of each jar after each of the questions.

Additional Extensions

Make individual cards or a recording sheet with pictures of the various jar combinations and questions about the probability of picking out a specific colored marble. Make room for the answer. Allow the children to work on and answer the cards individually. When everyone is finished with their work, bring the children together to talk about their answers.

• Probability: The chance that something is going to happen (e.g.,”What is the probability that I will pick out a green marble?”)
• Certain: Inevitable; will definitely happen (e.g.,“Is it certain that I will pick out a green marble?”)
• Impossible: No chance that a particular event will happen (e.g.,”Is it impossible to pick a blue marble out of this jar of all orange marbles?”)
• Possible: A chance that something might happen (e.g.,”Is it possible that I might pick a green marble out of the jar?”)

Early Math Glossary

Adapt Lesson for Toddlers

Toddlers may:

• Not yet grasp the concept of probability

Child care providers may:

• Just begin with certain and impossible and only show the jars and ask the questions that would result in the children answering certain or impossible
• After reviewing certain and impossible, build possible into the repertoire of questioning

Adapt Lesson for Preschoolers

Preschoolers may:

• Work independently

Child care providers may:

• Make individual cards or a recording sheet with pictures of the various jar combinations and questions about the probability of picking out a specific colored marble. Make room for the answer. Allow the children to work on and answer the cards individually. When everyone is finished with their work, bring the children together to talk about their answers.