Benchmark 12B
Habits of Mind: Computation and Estimation
Grades 6-8, page 291

Determine what unit (such as seconds, square inches, or dollars per tankful) an answer should be expressed in from the units of the inputs to the calculation, and be able to convert compound units (such as yen per dollar into dollar per yen, or miles per hour into feet per second).
 

NSES Content Standard A 
Science as Inquiry: Abilities necessary to do scientific inquiry
Grades 5-8, page 148
Use mathematics in all aspects of scientific inquiry. Mathematics is essential to asking and answering questions about the natural world. Mathematics can be used to ask questions, to gather, organize and present data, and to structure convincing explanations.