What is the order of operations in math?
The order of operations is the agreed sequence for evaluating an expression: parentheses first, then exponents, then multiplication and division from left to right, then addition and subtraction from left to right. Without it the same expression would have several answers. Many students remember it as PEMDAS.
Order of Operations in a picture
Formal definition and notation
To evaluate an expression: (1) simplify inside grouping symbols, such as parentheses, brackets, braces, a fraction bar or absolute value bars, working from the innermost group out; (2) evaluate exponents and roots; (3) do all multiplication and division in order from left to right, because the two have equal priority; (4) do all addition and subtraction from left to right, also with equal priority. The order is a convention that everyone agrees on, so that a written expression has exactly one value.
| Symbol | Read it as | Meaning |
|---|---|---|
| ( ) [ ] { } | parentheses, brackets, braces | grouping symbols: work inside them first, innermost first |
| 8 + 42 + 1 | 8 plus 4, over 2 plus 1 | a fraction bar groups the top and the bottom: 12 ÷ 3 = 4 |
| 52 | five squared | an exponent, done before any multiplication: 2 × 52 = 50 |
Key facts
- Multiplication does not always come before division: 24 ÷ 4 × 2 = 6 × 2 = 12, working left to right.
- Addition does not always come before subtraction: 10 − 4 + 3 = 6 + 3 = 9.
- Grouping symbols include brackets, braces, a fraction bar and absolute value bars, not only parentheses.
- An exponent applies only to what it touches: −32 = −9, but (−3)2 = 9.
- Scientific calculators follow the order of operations, so type parentheses where you want something done first.
PEMDAS: the order, step by step
- P
- parentheses and other grouping symbols
- E
- exponents (and roots)
- MD
- multiplication and division, one tie, left to right
- AS
- addition and subtraction, one tie, left to right
A memory aid is Please Excuse My Dear Aunt Sally. M is not ahead of D, and A is not ahead of S: in each pair, whichever comes first from the left goes first. BODMAS, BIDMAS and GEMDAS name the same order.
Order of Operations examples, step by step
Example 1: Division and multiplication tie
Evaluate 18 − 6 ÷ 3 × 2.
- No parentheses or exponents. Multiplication and division come next, left to right.
- Division is first from the left: 6 ÷ 3 = 2, giving 18 − 2 × 2.
- Then multiply: 2 × 2 = 4, giving 18 − 4.
- Subtract: 18 − 4 = 14.
Answer: The value is 14.
Example 2: Nested grouping symbols
Evaluate 5 × [2 + (9 − 4)2] − 33.
- Innermost parentheses first: 9 − 4 = 5, so the brackets hold 2 + 52.
- Exponent inside the brackets: 52 = 25, so the brackets hold 2 + 25 = 27.
- Now the expression is 5 × 27 − 33. Exponent: 33 = 27.
- Multiply: 5 × 27 = 135. Subtract: 135 − 27 = 108.
Answer: The value is 108.
Example 3: A negative sign and an exponent
What is the value of −22 + 10 ÷ (1 + 4)?
- Parentheses: 1 + 4 = 5.
- Exponent: 22 = 4. The minus sign is not inside parentheses, so −22 = −4.
- Division: 10 ÷ 5 = 2.
- Add: −4 + 2 = −2. The trap answer 6 comes from squaring −2.
Answer: The value is -2.
Common mistakes
Multiplication and division are done left to right; addition and subtraction are also done left to right. Neither one in a pair outranks the other.
Multiplication comes before addition, wherever it sits in the expression.
Addition and subtraction tie, so go from left to right. The subtraction comes first here.
The exponent applies to the 3 alone; the minus sign is applied after the exponent.
Not to be confused with
An expression is the math phrase itself, like 2 + 3 × 4. The order of operations is the rule you follow to find its value, 14.
The distributive property is a second, legal path that gives the same value: 4(6 + 2) = 4 × 8 = 32 and also 24 + 8 = 32. It does not break the order of operations.
Quick check: 3 questions
Evaluate 20 − 12 ÷ 4 + 1.
Answer: A. Divide first: 12 ÷ 4 = 3. Then left to right: 20 − 3 = 17 and 17 + 1 = 18. Choice B subtracts before dividing, C adds 3 + 1 before subtracting, and D treats the expression as (20 − 12) ÷ (4 + 1).Show answer and explanation
Which operation comes first in 7 + 3 × (8 − 2)2?
Answer: C. Parentheses come first: 8 − 2 = 6. The exponent then squares the whole group, 62 = 36, so squaring only the 2 is wrong. The full value is 7 + 3 × 36 = 115.Show answer and explanation
What is −42 + 3 × 2?
Answer: B. −42 = −16 (the exponent goes on the 4 only), and 3 × 2 = 6, so −16 + 6 = −10. Choice A squares −4, C adds before multiplying, and D does both.Show answer and explanation
Order of Operations: frequently asked questions
Does multiplication always come before division?
No. Multiplication and division have the same rank, so you do whichever comes first as you read from left to right. In 12 ÷ 3 × 2 you divide first and get 8, not 2. The same goes for addition and subtraction. PEMDAS lists M before D and A before S only because a word has to put its letters in some order.
What is the difference between PEMDAS and BODMAS?
Only the names. PEMDAS (parentheses, exponents, multiplication and division, addition and subtraction) is common in the United States. BODMAS uses brackets and orders (or of), and BIDMAS uses indices, but the order of the steps is the same. GEMDAS says grouping to remind you that brackets, fraction bars and absolute value bars count too.
Why do we need an order of operations?
Without one, a single expression could have several values. Working left to right, 2 + 3 × 4 would be 20; doing the multiplication first gives 14. Agreeing on one order means everyone, including every calculator and spreadsheet, gets 14. It also lets you write expressions with fewer parentheses.
Practice and tools
Sources
- Common Core State Standards, Grade 5 Operations and Algebraic Thinking (5.OA.A.1)
- Common Core State Standards, Grade 6 Expressions and Equations (6.EE.A.2.c, Order of Operations)
- OpenStax, Prealgebra 2e, 2.1 Use the Language of Algebra (order of operations)
Updated November 2026·Reviewed by the Effortless Math team·Standards: CCSS 5.OA.A.1, CCSS 6.EE.A.2.c
Cite this entry
Effortless Math Team. “Order of Operations.” Effortless Math Dictionary. Updated November 2026. https://www.effortlessmath.com/math-dictionary/order-of-operations/
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