There are plenty of things in math and physics (like special relativity or vector calculus) that seem hard but are in fact simple once you understand them. Then there are a other things, instead, that seem really simple, but they are actually hard.
I find that some software engineers and computer scientists have a superficial understanding of units and reference systems, and hold to some common but flawed ideas.
Units are symbols
In the simplest case, the unit is a symbol we stick after a number: 5 m, 3 sec, 1 pound... But clearly that does notapply to everything, as in m/s for velocity or m/s2 for acceleration. Units are expressions.
So, if you store a unit in a string, that