What Are the Chances?
Explain to your students that they are going to play some games and take part in simple experiments to demonstrate probability situations.
Rolling the Dice
Provide pairs of students with two dice. (To make inexpensive, light weight dice, buy cubes of foam rubber, which is available in craft stores, and paint numbers on each side with nail polish).
Invite the students to take turns throwing the dice. After each turn, ask them to record the two numbers that are on top. After ten turns each, ask them to compare the numbers. Were any the same? How often did the six show up? Is this a reliable method of predicting what numbers the dice will roll?
What's in the Bag?
Provide pairs of students with a bag containing an equal number of red, blue and green blocks. Invite the students to predict what color block they will pull out of the bag, and then ask them to take turns reaching into the bag and pulling out a block.
After each turn, ask them to record their prediction and the color of the block they pulled out. After five turns each, discuss how many times their prediction was correct. Is this a sure way to predict what color will come out of the bag every time? When working with first grade students, it is important in this experiment that they understand that there is no right or wrong prediction; the results are entirely by chance.
Race to the Finish
Gather the students around a ramp made by a large wooden block from the block center balanced on another smaller block. Show the students two small toy cars and ask them which one they think will win the race down the ramp. Mark a finishing line with masking tape and set the two cars racing at the same time. After each race, record the result on a chart. After ten races, discuss the results with the students. Did the same car win each race? Why or why not?
Spin and Guess
Provide small groups with spinners (These are readily available in discount or "dollar" stores or as parts of games). Invite the students to predict where the spinner will stop and take turns experimenting. Ask them to record the results. Discuss the randomness of the results.
Bean Bag Toss
Make a scoreboard (similar to a dartboard) from a large sheet of cardboard. Provide bean bags and ask students to throw the bean bags onto the board. Record the number that the bean bag lands on each time. Was there any consistency?
Set up the scenario that at the beginning of certain games - especially sports games - there is often a coin toss. Each pair of children will consist of a referee and a player. The referee tosses the coin and the player calls heads or tails. After each coin toss, students change roles. Does the player always choose the right call? Why or why not? Is this purely by chance?
Boy or Girl?
Gather the students together and tell them that you are going to write a name of one of the students on a piece of paper. Invite them to write on their piece of paper "boy" or "girl". Reveal the name and see how many guessed correctly. Repeat with more names. Discuss how there is no pattern or reason to this method of choosing.