Simple Science: Probability

Contributed by Abbey Faulkey, Sunrise Valley ES Math Specialist

Did you know you can experiment with math? Probability is a type of math that measures the chance of something happening, like flipping a coin and getting heads or tails. Probability is used in various fields like statistics, science, engineering, and finance to make predictions about future events. It’s like a science experiment because you make a prediction, test it, and see what happens. Sometimes the results match your guess, but other times they surprise you! Try it for yourself!

Coin Flip

Challenge Level (two stars)

Question: How often will a coin land on heads or tails when it is flipped a certain number of times?

Materials: two-sided coin, paper and pencil

Steps:

• Decide how many times you will flip your coin (ex: 5, 10, 20)

• Flip the coin.

• Record if it lands ‘heads’ or ‘tails’

Predict: I think the coin will land on (heads or tails) more.

Explain: What did you notice? What did you wonder?

When you flip a coin, it can land on either heads or tails because it has two sides. Each time you flip, there’s a fair chance it could be heads or tails, but the coin doesn’t "remember" past flips—it’s always a fresh start! So, even if you flip it many times, the results might not be exactly even because randomness can lead to little surprises.

Horse Race

Challenge Level (three stars)

Question: How often will a pair of dice show a certain sum (numbers 2-12)?

Materials: a pair of six-sided die, paper, pencil

Steps:

• Write the numbers 2-12 on a piece of paper.

• Decide how many times you will roll the pair of dice.

• Choose which number you think will be rolled the most often. (This is the ‘horse’ you believe will win the race).

• Roll the pair of dice.

• Record which number is rolled by placing an X next to that number on your paper.

• Note which number has more Xs, or which ‘horse’ came out ahead.

Predict: I think the number ___ will be rolled more often.

Explain: What did you notice? What did you wonder?

When you roll two dice, each die has six sides, so there are many possible results. The sample set is all the different number combinations you could roll, like 2+1, 3+4, or 6+6. Some sums, like 7, happen more often because there are more ways to roll them, while others, like 2 or 12, are rarer since there’s only one way to get them! (CHALLENGE: What are all the ways to roll each number, 2 through 12, using a pair of six-sided die?)

Magic Hat

Challenge Level (four stars)

Question: How often will you pull a certain color item from a bag?

Materials: a handful of Legos, dried color cereal, or other small colored objects; paper and pencil, bag or other container.

Steps:

Put a handful of small colored items into a bag. (Make sure you can’t easily see through the bag or into the container.)

Decide how many times you will choose an item from the bag.

Choose one item from the bag at a time.

On your paper, record which color was picked. Put the item back into the bag before you choose again.

Predict: The color ___ is most likely to be chosen.

Explain: Do you have the same amount of each color? How might that affect the chances of one color being pulled over another? Which colors are unlikely to be chosen? Are there any that are impossible to get?

Picking items with replacement means that after you pick something, you put it back before picking again. This keeps the total number of items the same each time, so the probability doesn’t change. For example, if you have 5 red marbles and 5 blue marbles in a bag, the chance of picking a red one stays 5 out of 10 every time because you always put it back!