# Sampling and Estimating: How Many Jellybeans

## Mathematical goals

This lesson unit is intended to help you assess how well students are able to:

- Model a situation mathematically, justifying any assumptions made.
- Estimate unknown values/missing information when solving a problem.
- Calculate volumes of three-dimensional objects.
- Use an appropriate sampling method to draw conclusions about a population.

## Introduction

- Before the lesson, students attempt the
*Jellybeans*task individually. You then assess their responses and formulate questions that will prompt students to review their work. - At the start of the lesson, students think individually about their responses to the questions set.
- Next, students work in small groups to combine their thinking and work together to produce a collaborative solution to the
*Jellybeans*task, in the form of a poster. - In the same small groups, students evaluate and comment on sample responses, identifying the strengths and weaknesses in each approach and comparing them with their own work.
- In a whole-class discussion students compare and evaluate the methods they have seen and used.
- In a follow-up lesson, students reflect on their work and what they have learned.

## Materials required

- Each student will need a copy the assessment task:
*Jellybeans*(printed in color, if possible), a copy of the questionnaire*How Did You Work?*and some plain paper to work on.

Calculators should be made available on request.

- Each small group will need a large sheet of paper and copies of
*Sample Responses to Discuss*. - There is a projector resource to support whole-class discussions.

## Time needed

20 minutes before the lesson for the assessment task, a 100-minute lesson (or split into two shorter lessons), and 15 minutes in a follow-up lesson (or for homework). Timings given are only approximate. Exact timings will depend on the needs of the class.

## Lesson Type

## Mathematical Practices

This lesson involves a range of *mathematical practices* from the standards, with emphasis on:

- MP1: Make sense of problems and persevere in solving them
- MP2: Reason abstractly and quantitatively
- MP3: Construct viable arguments and critique the reasoning of others
- MP4: Model with mathematics
- MP5: Use appropriate tools strategically
- MP6: Attend to precision

## Mathematical Content Standards

This lesson asks students to select and apply mathematical content from across the grades, including the *content standards:*