**Objective:** Students will weigh M and M’s and count the number of M and M’s. Using their data, they will write an

equation predicting the

weight of M and M’s from the number.

**Note:** Activity can be changed to use any quantity that can be counted and weighed. Non-food alternatives could include: beads, counting chips, centimeter cubes.

**Prior Knowledge:****Materials:**- Large bags of M and M’s or an alternative material listed above
- Styrofoam cups, 1 for each group
- Triple-beam balance, 1 for each group
- 3-oz paper cups, one for each student
- Paper plates or paper towels for each student

**Group Size:** 4-6 students

**Time Frame:**- Background: 10 minutes
- Distributing and weighing samples : 20 minutes
- Plotting points and calculating a linear regression equation: 10 minutes
- Follow-up questions: 10 minutes
- Clean-up: 10 minutes

**Procedure:**- Before weighing the M and M’s, the styrofoam cup must be weighed empty, and this weight recorded. This weight will be subtracted from the total weight each time a student weighs their M and M’s.

- Each person in the group will fill his/her paper cup with M and M’s.One at a time, the student will pour his/her cup of M and M’s into the Styrofoam cup and weigh it. Record the net weight (Total weight – weight of cup). The student will then pour the M and M’s back into his/her cup or on the paper plate or paper towel.

- Count the number of M and M’s. Each student should make sure the recorder correct records his/her sample number and weight.

- Assign a recorder to make the table of values to be recorded shown below.

**Student Name** | **Total Number** of M and M's | **Net Weight** of M and M's |

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**Student Worksheet and Conclusions**- Make a scatterplot of the data, putting number of M and M’s on the horizontal axis and their net weight on the vertical axis. Label the axes with uniform scales.

- Using a straightedge, draw a trend line on your data that you feel best fits the data.

- Identify two grid points on your trend line (do NOT use data points). Write down their coordinates:
Point 1: ( , )

Point 2: ( , )

- Find the slope of your trend line.

- Write the equation of your trend line.

- What is the y-intercept of your trend line? Do you get the same answer looking at the graph as you do using your equation? What does this number represent? Does this make sense?

- Using your equation, predict the weight of 1000 M and M’s.

- What is the meaning of the slope of your trend line? Describe this rate of change in words.

**Extension: **Each student in your group probably has a different

slope and

y-intercept for his/her

equation of the trend line, and therefore, has made different predictions for the

weight of 1000 M and M’s. Describe a way that you could combine the information of your team members to create a better trend

line equation.