The Myth

Ask most people and they will say multiplication comes before division in BEDMAS. This is one of the most persistent misconceptions in mathematics — and it is reinforced by the order of letters in BEDMAS, PEMDAS, and every other acronym variant. The acronym is misleading: the letters are grouped to form a pronounceable word or memorable phrase, not to indicate strict sequential priority within each group.

The Truth: They Are Equal Priority

Multiplication and division have identical precedence in the order of operations. When they appear together in an expression — with no brackets to indicate otherwise — you evaluate them strictly from left to right, whichever comes first in the written expression. In 12 ÷ 4 × 3, you work left to right: 12 ÷ 4 = 3, then 3 × 3 = 9. The answer is 9, not 1. If you calculated 4 × 3 = 12 first, you would need brackets to justify it: 12 ÷ (4 × 3).

The Same Is True for Addition and Subtraction

The same principle applies one level down: addition and subtraction are equal priority and are evaluated left to right. 10 − 3 + 2 is not 5 — it is 9. Working left to right: 10 − 3 = 7, then 7 + 2 = 9. Addition does not come before subtraction. They are equal; left to right is the tiebreaker.

Why This Matters in Practice

This error appears most commonly in spreadsheet formulas and code. A programmer writing result = a / b * c expecting it to mean a / (b * c) will get (a / b) * c instead — potentially a very different number. In financial modelling, engineering calculations, and scientific code, this kind of precedence error can produce results that are completely wrong but plausible-looking. Understanding the true rule — left to right for equal-priority operators — eliminates this entire class of error permanently.