Four operations, but underneath them only two. Addition and multiplication are the genuine ones, each carrying the same freedoms of order and grouping. Subtraction and division are those two seen in a mirror, reached through the opposite and the reciprocal. Here is the whole chapter on a single page, section by section.
That is the whole toolkit of Chapter 1. Everything ahead, exponents, primes, fractions, and the algebra past them, is built on these same rules.
QuanticaPrealgebraOpen in the course