Learn on PengienVision, Mathematics, Grade 7Chapter 7: Probability

Lesson 1: Understand Likelihood and Probability

In this Grade 7 lesson from enVision Mathematics Chapter 7, students learn what probability is and how to express it as a ratio or percent on a scale from 0 to 1. Using spinners and number cubes, students practice describing the likelihood of outcomes as impossible, unlikely, likely, or certain, and determine whether a spinner is fair based on equally likely outcomes.

Section 1

Understanding Equally Likely Outcomes and Fairness

Property

Outcomes are equally likely when each outcome has the same chance of occurring. The basic probability formula P(event)=number of favorable outcomestotal number of possible outcomesP(\text{event}) = \frac{\text{number of favorable outcomes}}{\text{total number of possible outcomes}} only applies when all outcomes are equally likely.

Examples

Section 2

Fairness: When Outcomes Are Not Equally Likely

Property

Not all outcomes are equally likely just because they exist. Equal probability requires either experimental evidence or knowledge that outcomes have the same chance of occurring. When outcomes are not equally likely, theoretical probability cannot be calculated as P(event)=number of favorable outcomestotal number of outcomesP(\text{event}) = \frac{\text{number of favorable outcomes}}{\text{total number of outcomes}}.

Examples

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Chapter 7: Probability

  1. Lesson 1Current

    Lesson 1: Understand Likelihood and Probability

  2. Lesson 2

    Lesson 2: Understand Theoretical Probability

  3. Lesson 3

    Lesson 3: Understand Experimental Probability

  4. Lesson 4

    Lesson 4: Use Probability Models

  5. Lesson 5

    Lesson 5: Determine Outcomes of Compound Events

  6. Lesson 6

    Lesson 6: Find Probabilities of Compound Events

  7. Lesson 7

    Lesson 7: Simulate Compound Events

Lesson overview

Expand to review the lesson summary and core properties.

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Section 1

Understanding Equally Likely Outcomes and Fairness

Property

Outcomes are equally likely when each outcome has the same chance of occurring. The basic probability formula P(event)=number of favorable outcomestotal number of possible outcomesP(\text{event}) = \frac{\text{number of favorable outcomes}}{\text{total number of possible outcomes}} only applies when all outcomes are equally likely.

Examples

Section 2

Fairness: When Outcomes Are Not Equally Likely

Property

Not all outcomes are equally likely just because they exist. Equal probability requires either experimental evidence or knowledge that outcomes have the same chance of occurring. When outcomes are not equally likely, theoretical probability cannot be calculated as P(event)=number of favorable outcomestotal number of outcomesP(\text{event}) = \frac{\text{number of favorable outcomes}}{\text{total number of outcomes}}.

Examples

Book overview

Jump across lessons in the current chapter without opening the full course modal.

Continue this chapter

Chapter 7: Probability

  1. Lesson 1Current

    Lesson 1: Understand Likelihood and Probability

  2. Lesson 2

    Lesson 2: Understand Theoretical Probability

  3. Lesson 3

    Lesson 3: Understand Experimental Probability

  4. Lesson 4

    Lesson 4: Use Probability Models

  5. Lesson 5

    Lesson 5: Determine Outcomes of Compound Events

  6. Lesson 6

    Lesson 6: Find Probabilities of Compound Events

  7. Lesson 7

    Lesson 7: Simulate Compound Events