Maths goes in two ways: a Math Block for an equation that sits on its own line, and Inline Math for a symbol or expression inside a sentence. Both open the same editor.

Type /math and pick either Math Block or Inline Math, or choose one from the + menu. A small editor opens with three tabs.

The default. Type and the expression builds itself as you go, fractions and exponents laid out properly rather than as code. This is the one to use if LaTeX is not something you think in.

Type LaTeX directly, for example \frac{a}{b} + \sqrt{c} in a block, or x^2 inline. Faster if you already know the syntax, and the right choice when you are pasting expressions from something you have already written.

Describe the equation in plain words and it converts it for you. "the integral from 0 to 1 of x squared" comes back as a properly typeset integral. Click Convert, check the preview, then Use this equation, or Try again to reword it.

Handy for the expression you can picture but cannot remember the LaTeX for. Always look at the preview before you accept it.

Under both the Visual Editor and LaTeX tabs there is a symbol picker, grouped into Common, Greek, Calculus, Trig, Sets and Matrix. There is a search box, so typing what you are after is usually quicker than hunting through the tabs. Click a symbol to drop it in at the cursor.

Inline maths works inside a question prompt, in multiple choice options and in a mark scheme, so a question and its answers can all be properly typeset. Students get the same maths editor when they answer, so they can write a real expression back rather than trying to describe one in words. See Answering with images, drawings or maths.