Order of Operations (BODMAS) — Definition, Formula & Examples
Order of Operations (BODMAS) is the rule that tells you the sequence in which to perform calculations in a mathematical expression. BODMAS stands for Brackets, Orders (exponents), Division, Multiplication, Addition, and Subtraction.
BODMAS is a convention that establishes a hierarchy for evaluating arithmetic expressions: first evaluate expressions inside grouping symbols (brackets/parentheses), then apply exponents (orders/powers), then perform division and multiplication from left to right, and finally perform addition and subtraction from left to right. This convention ensures that every well-formed numerical expression yields a single, unambiguous result.
How It Works
When you see an expression like , you need a rule to decide whether to add first or multiply first — different choices give different answers. BODMAS provides that rule. Work through each level in order: simplify anything inside Brackets first, then evaluate Orders (exponents), then carry out Division and Multiplication scanning left to right, and finally handle Addition and Subtraction scanning left to right. Note that Division and Multiplication share the same priority — whichever appears first from left to right gets done first. The same applies to Addition and Subtraction. The acronym PEMDAS (Parentheses, Exponents, Multiplication, Division, Addition, Subtraction) describes exactly the same rule using different names.
Worked Example
Problem: Evaluate
Brackets: Simplify the expression inside the brackets first.
Orders (Exponents): Next, evaluate the exponent.
Multiplication: Now perform the multiplication.
Addition: Finally, perform the addition.
Answer:
Another Example
Problem: Evaluate
Division and Multiplication (left to right): Division and multiplication have equal priority, so work left to right. Division comes first.
Continue Multiplication: Now multiply.
Addition: Finally, add.
Answer:
Why It Matters
Order of operations is foundational to every math course from middle-school pre-algebra through calculus. Spreadsheet formulas, programming languages, and scientific calculators all follow these same rules, so entering a formula incorrectly can produce wrong answers in real-world work. Understanding BODMAS also prepares you for writing and simplifying algebraic expressions, where misapplying the order leads to errors that cascade through multi-step problems.
Common Mistakes
Mistake: Always doing multiplication before division (because M comes before D in PEMDAS)
Correction: Multiplication and division have equal priority. Evaluate them left to right. For example, in , divide first to get , not .
Mistake: Ignoring brackets and jumping straight to multiplication or exponents
Correction: Brackets always come first. In , you must add inside the brackets to get before multiplying, giving — not .
