Ability to read algebra
This requisite asks whether you can read a sentence that throws in algebra or a mathematical concept, without slowing down too much. For instance, a sentence remarking that in the limit of flipping N coins each with a 1/N probability of coming up heads, the chance of never getting heads is 1/e. If that kind of sentence is one you can read, you should mark yourself as understanding this requisite, so you will automatically be shown Arbital pages and tabs that invoke math of that level.
Mathematics is the study of numbers and other ideal objects that can be described by axioms.