Citizen Math used to be called Mathalicious. If you have a current account on Mathalicious, you can use those credentials to log in to your Citizen Math account. Learn more here.  # Happy Meal

## How much would it cost to get all the toys in a Happy Meal? How much would it cost to get all the toys in a Happy Meal? The McDonald’s Happy Meal is a cultural phenomenon. Parents like it because it’s a quick and easy meal, and kids like it because it comes with a toy (typically part of a larger set).

Students use trials, probabilities, and expected value to determine how many meals it takes to get a complete set of Happy Meal toys and debate whether McDonald’s should allow customers to pay a fee to choose their own figurine.

### REAL WORLD TAKEAWAYS

• When trying to collect a full set of Happy Meal toys, the chance of getting a new toy decreases as you collect more toys.
• The expected cost of acquiring a new toy, then, also increases.

### MATH OBJECTIVES

• Create frequency distribution from experimental data and interpret the results
• Use theoretical and experimental probability to reason about real-world decisions
• Calculate expected value and use it to evaluate decisions in a real-world context

This complex task is best as a culminating unit activity after students have developed formal knowledge and conceptual understanding. Algebra 1
Probability (Beg.) Algebra 1
Probability (Beg.)
Content Standards S.ID.1 Represent data with plots on the real number line (dot plots, histograms, and box plots). S.IC.2 Decide if a specified model is consistent with results from a given data-generating process, e.g., using simulation. For example, a model says a spinning coin falls heads up with probability 0.5. Would a result of 5 tails in a row cause you to question the model? S.CP.2 Understand that two events A and B are independent if the probability of A and B occurring together is the product of their probabilities, and use this characterization to determine if they are independent. S.CP.5 Recognize and explain the concepts of conditional probability and independence in everyday language and everyday situations. For example, compare the chance of having lung cancer if you are a smoker with the chance of being a smoker if you have lung cancer. S.CP.7 Apply the Addition Rule, P(A or B) = P(A) + P(B) - P(A and B), and interpret the answer in terms of the model. S.MD.4 (+) Develop a probability distribution for a random variable defined for a sample space in which probabilities are assigned empirically; find the expected value. For example, find a current data distribution on the number of TV sets per household in the United States, and calculate the expected number of sets per household. How many TV sets would you expect to find in 100 randomly selected households? S.MD.7 (+) Analyze decisions and strategies using probability concepts (e.g., product testing, medical testing, pulling a hockey goalie at the end of a game).
Mathematical Practices MP.1 Make sense of problems and persevere in solving them. MP.2 Reason abstractly and quantitatively. MP.3 Construct viable arguments and critique the reasoning of others. MP.4 Model with mathematics. MP.5 Use appropriate tools strategically. MP.7 Look for and make use of structure. MP.8 Look for and express regularity in repeated reasoning.