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Decomposers | Activity 3.1

Activity 3.1: Predictions about Bread Molding (50 min)

Students use the Predictions Tool to record their predictions about what happens when bread molds.

Materials You Provide

Resources Provided


Print one copy of 3.1 Predictions Tool for Bread Molding for each student. Prepare a computer and projector to display the PPT and the video. Print one copy of the Three Questions 11 x 17 Poster and display it on your classroom wall. Print one copy of the Three Questions Handout for each student. Retrieve the materials from Activity 1.2. This may include a ppt slide from the lesson in which you typed students’ responses or a photograph of their sticky notes as well as the students’ completed 1.2 Expressing Ideas Tool for Plants Growing.


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


The Three Questions will be a review from the Systems and Scale, Plants, and/or Animals units, but Level 2 students may still find the questions themselves hard to understand. In particular, they may be unable to connect the three columns in the Three Questions 11 x 17 Poster. Note whether students use facts about matter and energy as they try to answer the Three Questions.

During the class, listen to the ideas students offer in the final step of the activity. Do students’ predictions follow the rules? At this point, do not correct student ideas, but listen for what they say about matter and energy in the context of decomposition. After class, use the 3.1 Assessing the Predictions Tool for Bread Molding to compare your students’ ideas with what we would expect to see in Level 4 responses.

This discussion will show that some students are still at Level 2 with respect to both their ideas about energy and their understanding of the questions. For example, do students have a sense of necessity about the connections between mass changes and movement of atoms? Do they recognize that if the bread loses mass, then atoms must be moving out of the bread? Do students account for energy separately from matter, or do they suggest that some of the matter in the bread and mold might be converted to energy or disappear? You do not need to correct any problems now; they will be addressed through the investigation and Modeling in the Activities to come.


  • Have a designated place in the classroom where students store their 3.1 Predictions Tool for Bread Molding so they can easily refer back to their ideas at the end of the lesson.
  • Expect many students to make the right predictions for the wrong reasons. Note in particular whether they say that changes in the mass of the bread indicate that atoms are moving.