Estimating Probabilities through Repeated Experiments

5 min

Narrative

The purpose of this Warm-up is for students to practice placing numbers represented with decimals on a number line and thinking about probabilities of events that involve the values of the numbers. Values between 0 and 1, such as the ones found here, are related to probabilities students will see in later activities. They will also need to be able to plot probabilities.

Launch

Arrange students in groups of 2. Give students 2 minutes of quiet work time followed by time to share their responses with a partner. Follow with a whole-class discussion. 

Student Task

  1. Locate and label these numbers on the number line.

    1. 0.5
    2. 0.75
    3. 0.33
    4. 0.67
    5. 0.25

    Number line with tick marks at 0 and 1

  2. Choose one of the numbers from the previous question. Describe a game in which that number represents your probability of winning.

Sample Response

  1.  
    <p>Number line. </p>
  2. Sample response: Get blue when randomly selecting a color from the primary colors: red, yellow, and blue. This has a probability of 0.33.

Synthesis

Select some partners to share their responses and methods for positioning the points on the number line. If time allows, select students to share a chance event for each of the values listed.

Standards
Building On
  • 5.NBT.3·Read, write, and compare decimals to thousandths.
  • 5.NBT.A.3·Read, write, and compare decimals to thousandths.
Addressing
  • 7.SP.7·Develop a probability model and use it to find probabilities of events. Compare probabilities from a model to observed frequencies; if the agreement is not good, explain possible sources of the discrepancy.
  • 7.SP.C.7·Develop a probability model and use it to find probabilities of events. Compare probabilities from a model to observed frequencies; if the agreement is not good, explain possible sources of the discrepancy.

20 min

10 min