Fighting Fleas

Exponential Decay

The students move to decay factors that are expressed in percents and learn to distinguish between growth factors and growth rates. The focus is on evidence of student understanding, and the teacher's role in assessing understanding and adding value to the Summary phase.

The vieo concludes with the teacher reflecting on the lesson.

Real time is about 55 minutes.

As you view the video, consider the following:

• What is the evidence of students’ understanding and reasoning? What prior understandings do you see students using or building upon?
• What is the evidence of students’ understanding and reasoning? What prior understandings do you see students using or building upon?
• What is the evidence of students’ use of the mathematical practices from the Common Core State Standards? To what extent are students growing in their sophistication of their use of the practices?
• Were there any “aha moments” in the video?
• How is the teacher facilitating the development of students’ understanding and reasoning?
• As a teacher, how would you use the information from this lesson to plan the next lesson?

• Full Length (22:24)
• CMP2 Problem 4.2
• CMP3 Problem 4.2 Part 1
• CMP3 Problem 4.2 Part 2
• Goals for Investigation 4
  •  Use knowledge of exponential relationships to make tables and graphs and to write equations for exponential decay patterns
  • Analyze and solve problems involving exponents and exponential decay
  • Recognize patterns of exponential decay in tables, graphs, and equations
  • Use information in a table or graph of an exponential relationship to write and equation
  • Analyze an exponential decay relationship that is represented by an equation and use the equation to make a table and graph
• Video Transcript
• Suggestions for organizing Professional Development