# The Standards

### Ecosystems: Interactions, Energy, and Dynamics

#### Students who demonstrate understanding can:

Use mathematical representations to support claims for the cycling of matter and flow of energy among organisms in an ecosystem HS-LS2-4

Clarification Statement and Assessment Boundary

Clarification Statement: Emphasis is on using a mathematical model of stored energy in biomass to describe the transfer of energy from one trophic level to another and that matter and energy are conserved as matter cycles and energy flows through ecosystems. Emphasis is on atoms and molecules such as carbon, oxygen, hydrogen and nitrogen being conserved as they move through an ecosystem.

Assessment Boundary: Assessment is limited to proportional reasoning to describe the cycling of matter and flow of energy.

##### Science and Engineering Practices

Using Mathematics and Computational Thinking

Mathematical and computational thinking in 9–12 builds on K–8 experiences and progresses to using algebraic thinking and analysis, a range of linear and nonlinear functions including trigonometric functions, exponentials and logarithms, and computational tools for statistical analysis to analyze, represent, and model data. Simple computational simulations are created and used based on mathematical models of basic assumptions.

##### Crosscutting Concepts

Energy and Matter

### Common Core State Standards Connections

Mathematics
• HSN-Q.A.1 - Use units as a way to understand problems and to guide the solution of multi-step problems; choose and interpret units consistently in formulas; choose and interpret the scale and the origin in graphs and data displays. (HS-LS2-4)
• HSN-Q.A.2 - Define appropriate quantities for the purpose of descriptive modeling. (HS-LS2-4)
• HSN-Q.A.3 - Choose a level of accuracy appropriate to limitations on measurement when reporting quantities. (HS-LS2-4)
• MP.2 - Reason abstractly and quantitatively. (HS-LS2-4)
• MP.4 - Model with mathematics. (HS-LS2-4)

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