Measure, compare, add and subtract: lengths (m/cm/mm); mass (kg/g); volume/capacity (l/ml)

What this means, in plain words

Capacity is how much a container holds. Volume is how much space something takes up.

Mass is how much there is of something, measured here in grams and kilograms.

Comparing asks which is larger or smaller. Ordering puts several of them in a line from smallest to largest.