Activity 3.2: Observing Bread Molding (60 min over 2 days)

Target Student Performance

Students record data about changes in mass and BTB when bread molds and reach consensus about patterns in their data.

Resources You Provide

Resources Provided

Recurring Resources


Prepare the BTB, digital balances, Petri dishes, containers, and the materials from the Pre-Lesson. Use the instructions on the BTB Information and Instructions Handout for details about how to prepare the BTB. If you plan to use the poster to record student data, re-post the poster on the wall. Print one copy of 3.2 Observing Bread Molding Worksheet for each student. Prepare a computer with an overhead projector to display the PPT and video. You may want to print one copy of BTB Color Handout for each group, but this is optional.


1. (Day 1) Use the instructional model to show students where they are in the course of the unit

Show slide 2 of the 3.2 Observing Bread Molding PPT.


  • Use the class discussion when you compare their data to Mrs. Drayton’s class to interpret how successful your students are at identifying patterns in the class data. Use the 3.2 Grading the Observing Bread Molding Worksheet to determine if your students had any trouble with data collection.
  • During this activity, note students' success in measuring changes in mass and BTB. Also note students' ability to reach a consensus about patterns in data and how they interpret results.
  • The discussions in steps 10 and 12 can be helpful for informal assessment in two ways: 1) It can help you assess your students’ skills in identifying sources of error and finding patterns in data, and 2) it can help you assess how well students identify the limits of the evidence. Do they recognize that the investigation does not fully answer the Matter Change Question or the Energy Question?


  • Be sure to collect results from the different groups and compare their measurements.
  • Discuss threats to accuracy of measurement.
  • Check to see if students can identify unanswered questions from the investigation.

  • Use strategic grouping to distribute strong speakers.
  • Have students explain aloud the investigation plan (to a partner, small group, or whole class) after reading it.
  • Prompt students to consider how this investigation is similar to the investigations in previously taught Carbon TIME units, so they can draw on those experiences when conducting this investigation.
  • Compare class data orally and on the spreadsheet or poster.
Extending the Learning
  • Follow the same procedures to investigate other types of decomposition, such as food scraps, grass clippings, leaves, or wood.