Free Math Guide

PEMDAS Explained

Learn the order of operations with clear rules, step-by-step examples, and the most common mistakes students should avoid.

PEMDAS is a way to remember the order in which operations should be completed when an expression contains more than one type of calculation. Following the same order ensures that everyone evaluating the expression reaches the same result.

The basic rule

What does PEMDAS stand for?

PEMDAS represents the sequence used to simplify a mathematical expression. Work through the operations in the following order:

P

Parentheses

Simplify expressions inside grouping symbols first.

E

Exponents

Evaluate powers and roots after grouping symbols.

MD

Multiply or Divide

Complete whichever appears first while moving left to right.

AS

Add or Subtract

Complete whichever appears first while moving left to right.

A useful memory phrase

“Please Excuse My Dear Aunt Sally” can help you remember the letters, but the letters should not be treated as six separate levels of priority.

The most important detail

Multiplication and division are equal

Multiplication does not automatically come before division. They have equal priority, so you complete them from left to right. The same rule applies to addition and subtraction.

24 ÷ 6 × 2
First:
24 ÷ 6 = 4
Division appears first from the left.
Then:
4 × 2 = 8
Complete the remaining multiplication.
Answer:
8
Common misconception: Multiplying first would incorrectly produce 24 ÷ 12 = 2.

One expression, one agreed answer

Why do we need an order of operations?

Consider this expression:

8 + 2 × 5

Adding first would give 50, while multiplying first gives 18. PEMDAS tells us to complete multiplication before addition:

Multiply:
8 + 10
Add:
18

Worked solutions

PEMDAS examples step by step

Example 1: Multiplication before addition

6 + 4 × 3
Multiply:
6 + 12
Add:
18

Example 2: Parentheses first

5 × (7 − 3) + 2
Parentheses:
5 × 4 + 2
Multiply:
20 + 2
Add:
22

Example 3: Exponents before multiplication

3 + 2² × 5
Exponent:
3 + 4 × 5
Multiply:
3 + 20
Add:
23

Example 4: Several operations

18 ÷ 3 + 2 × (5 − 1)
Parentheses:
18 ÷ 3 + 2 × 4
Divide:
6 + 2 × 4
Multiply:
6 + 8
Add:
14

What to watch for

Common PEMDAS mistakes

Adding before multiplying

Complete multiplication or division before moving to addition or subtraction.

Always multiplying before dividing

Multiplication and division have equal priority. Move from left to right.

Always adding before subtracting

Addition and subtraction also have equal priority. Move from left to right.

Ignoring grouping symbols

Parentheses, brackets, fraction bars, and radicals may all group parts of an expression together.

Doing too many steps at once

Rewrite the expression after each operation. This makes errors easier to spot and correct.

Ready to practice?

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Simplify expressions one operation at a time, receive immediate feedback, and use hints when you get stuck.

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