CCSS.Math.Content.HSS-MD.B.6

MathGrades 9–12Using Probability to Make Decisions

The standard

(+) Use probabilities to make fair decisions (e.g., drawing by lots, using a random number generator).

Common Core State Standards for Mathematics

What this standard means

Students need to use chance methods to choose fairly among people or options. They should be able to assign equal probabilities, explain why a method is fair or unfair, and design a simple random process such as cards, dice, slips of paper, or a random number generator.

Mastery looks like matching the number of outcomes to the situation and checking that each person or choice has the same chance. Students often get stuck when outcomes are not equally likely, such as using one die for three people, or when they confuse “random” with “fair.”

Ways to teach it

  • Hands-on activity: Have groups design a fair way to choose one student from five using a die, then test it with 30 trials.
  • Writing prompt: Explain whether flipping one coin to choose among three team captains is fair, and propose a better method.
  • Quick assessment: Give three selection methods and ask students to label each fair or unfair with one sentence of reasoning.
  • Real-world connection: Analyze how jury pools, lottery drawings, or school raffle winners use random selection to avoid favoritism.

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Related standards

Standard text verified against corestandards.org on July 10, 2026.

Page updated July 10, 2026.

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