Foundations

Distinguish part-to-part ratios, fractions of a whole and rates with units. Scale quantities together, compare unit rates, and explain when a relationship is proportional. Check zero cases, starting amounts and whether a result fits its context.

Read a graph’s quantities, units, ticks and context before judging its visual impression. Calculate differences, reference-based percentages and interval rates from the represented values; distinguish legitimate zoom from distorted spacing; and keep samples, interpolation, missing information, uncertainty and causal explanations separate.

Build an inspectable physics record, test and revise a bounded cart model, preserve processing history, and plan findable data with appropriate sharing conditions.

In a Euclidean right triangle, squared leg lengths sum to the squared hypotenuse length.

A confidence level describes repeated-sampling coverage of an interval procedure.

Current measures charge crossing a chosen surface per unit time.

The mole counts specified entities using the exact Avogadro constant.

An isotope delta compares a specified sample isotope ratio with the same ratio in a stated reference.

Relative atomic mass is dimensionless and depends on the isotope composition being averaged.

Molar mass converts a specified substance's amount into mass.

Concentration must declare its numerator and denominator.

A coordinate pair needs a reference surface, origin and convention.

Flattening Earth's curved reference surface requires a choice of distortions.

Height above a geometric reference is not automatically height above a gravity reference.

The astronomical unit and light-year measure lengths, with different defining conventions.

A source location or magnitude does not describe the shaking experienced at every site.

Celestial angular coordinates require a declared reference system and date conventions.