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.
Define appropriate quantities for the purpose of descriptive modeling.
Interpret parts of an expression, such as terms, factors, and coefficients.
Interpret expressions that represent a quantity in terms of its context.
Use the structure of an expression to identify ways to rewrite it.