Documentation

Student-friendly HTML, CSS, and JavaScript reference with examples

Sections

Basic Math

Math.round(4.5) // 5

Five operators do the math.

5 + 3   // 8  — add
5 - 3   // 2  — subtract
5 * 3   // 15 — multiply
5 / 3   // 1.666… — divide
5 % 3   // 2  — divide, but keep the remainder instead

% (modulus) is its own topic — that’s next up after this one.

Math Methods

Operators aren’t the whole story. A handful of Math methods cover the rest of what
you’ll reach for constantly.

Math.round(4.5)   // 5 — nearest whole number
Math.floor(4.9)   // 4 — always rounds down
Math.min(3, 7)    // 3 — the smaller of the two
Math.max(3, 7)    // 7 — the larger of the two