Measures

I've been writing this spreadsheet, and I've decided that what it needs is units, or rather measures

A measure is the amount of a thing, e.g., it's length, mass, duration, or some combination (length per duration is speed, for example)

A unit is the ratio of a measure to a standard (metres for length, seconds for duration, etc.), or some multiple of the ratio (feet, pounds, days).

Storing measures needs to keep track of it's dimensions, it's magnitude, and it's unit (we're keeping the unit for display).