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Do the Math!

DCIs: LS2.A: Interdependent Relationships in EcosystemsLS2.B: Cycle of Matter and Energy Transfer in Ecosystems; LS4.D: Biodiversity and HumansESS3.A: Natural Resources; ESS3.C: Human Impacts on Earth SystemsETS1.A: Defining and Delimiting Engineering ProblemsPS1.B: Chemical Reactions

SEPs: Asking questions (for science); Developing and using models; Planning and carrying out investigations; Analyzing and interpreting data; Using mathematics and computational thinking; Constructing explanations (for science);  Engaging in Argument from Evidence; Obtaining, Evaluating, and Communicating information

CCCs: Patterns; Cause and Effect: Mechanism and Explanation; Scale, Proportion, and Quantity; Systems and System Models; Energy and Matter: Flows, Cycles, and Conservation; Structure and Function; Stability and Change

CA EPs & Cs: 

Time: 2 Days, 45 minutes

Prep: Review Lesson Plan, Teacher Prep (for Lesson 12): Coordinate with FWS Park Ranger* for in class or video visit. If Park Ranger cannot come to class with game, coordinate and prepare materials for Microtrash Game Per Set up (4 players): 1 tub/ bucket; 1 cover for tub with 1 – 4 slots; lots of shell, bone, and microtrash (pieces: 25, 15, 30).

Anchoring Phenomena

Essential Question

What role does the California condor play in the California ecosystem, and how do changes in the ecosystem impact condors over time?



1. Introduction: Students watch the documentary the Condor’s Shadow, and write down questions on post it notes to add to the “Questions Board".

  • Watch the video (over 2 days if needed)

*Contact Park Ranger to request access to documentary:

Day 2

1. Do the Math!

  • Read through the worksheet with the students.

  • Explain the equation we use to find out how many pounds of deer meat are in Ventura County.

    • Some classes may need more assistance (walk through the problem’s equation with the correct values as a class) – use your discretion.

  • Students should aim to work independently, but may need assistance from their peers.

    • Students will need calculators​.

"Mule deer are a common sight in Ventura County’s wild spaces.  They are an important part of a food web that includes vegetation like trees and shrubs, consumers like rabbits, and secondary consumers, or predators, like foxes, snakes, and mountain lions. Creatures like California condors, and ravens, as well as the many microscopic fungi, and bacteria make up the scavengers and decomposers in the food web."


Important Facts:

- 170 lbs is the average weight of an adult mule deer.

- Carrying capacity is 40 deer per square mile (CDFW)

- Ventura County is 2208 square miles.


1. How many pounds of mule deer exist in our county? _______________________


2. If half of that population dies in any given year (hunting, natural causes), how many pounds of mule deer carcass would exist? ______________________


3. If half of the carcass is taken/eaten by the primary predator (human, mountain lion, etc.), then how many pounds of carcass remains in the environment for scavengers (like California condors) and decomposers?



4. If scavengers and decomposers did not exist, how could we dispose of carcasses throughout the environment?


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