What is Order of Operations?
Imagine you and a friend both solve the expression but get different answers — you get 14, your friend gets 11. Your friend is correct — the answer is 11, and by the end of this section you will understand exactly why!
This is exactly why mathematicians agreed on a universal set of rules for the order in which operations are performed. Without these rules, the same expression could give different answers depending on who solves it!
A set of agreed rules that tells us the sequence in which mathematical operations (brackets, exponents, multiplication, division, addition, subtraction) must be carried out in an expression.
These rules are remembered using the acronyms BEDMAS or BODMAS, which are two names for the same set of rules used in different countries.
Think of BEDMAS like getting ready for school in the morning. You can't put your shoes on before your socks — there's a correct order! Similarly, in maths, some operations must come before others.
In MYP Sciences, you will use these rules constantly — whenever you substitute values into a formula like or , you need to know which part to calculate first. Getting the order wrong means getting the wrong scientific answer!
BEDMAS / BODMAS — The Rules
Here is what each letter stands for:
| Letter | BEDMAS | BODMAS |
|---|---|---|
| B | Brackets | Brackets |
| E/O | Exponents | Orders (powers/roots) |
| D | Division | Division |
| M | Multiplication | Multiplication |
| A | Addition | Addition |
| S | Subtraction | Subtraction |
The order to follow is:
- Brackets first — work out everything inside parentheses ( ) first
- Exponents/Orders — evaluate powers and roots next
- Division and Multiplication — working left to right
- Addition and Subtraction — working left to right
Division and Multiplication have equal priority — you do them left to right, not always division before multiplication. The same applies to Addition and Subtraction — they have equal priority and are worked left to right.
A memory trick: Big Elephants Don't Mind Any Snakes — one way to remember the order! You could also invent your own sentence using the letters B, E, D, M, A, S.
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