How it works
When you see a math expression with different operations—like parentheses, exponents, multiplication, division, addition, and subtraction—you need to solve it in a special order. This is called the order of operations. You can remember it with the phrase PEMDAS:
- Parentheses first
- Exponents next
- Multiplication and Division (from left to right)
- Addition and Subtraction (from left to right)
Let's look at an expression with all these parts: 3 + 2^3 × (10 - 4) ÷ 4.
- Parentheses: Solve anything inside ( ).
- Exponents: Solve numbers with exponents (like 2^3).
- Multiplication and Division: Go left to right across the expression.
- Addition and Subtraction: Go left to right across the expression.
Always work step-by-step, writing down each part as you go.
Worked example
Evaluate: 5 + 3^2 × (8 - 2) ÷ 2
- 1
Step 1: Parentheses
Work out the part in ( ). 8 - 2 = 6, so rewrite as 5 + 3^2 × 6 ÷ 2
- 2
Step 2: Exponents
Calculate 3^2. That's 3 × 3 = 9. Now the expression is 5 + 9 × 6 ÷ 2
- 3
Step 3: Multiplication and Division (left to right)
Start with 9 × 6 = 54. Now it's 5 + 54 ÷ 2. Next, 54 ÷ 2 = 27. Now it's 5 + 27
- 4
Step 4: Addition
Finally, add: 5 + 27 = 32.
Answer
32
Common mistakes
- 01
Doing addition before multiplication or division
Why: Some students just go left to right without following PEMDAS.
Avoid it: Always do multiplication and division before addition and subtraction.
- 02
Ignoring exponents or solving them last
Why: Students might skip exponents or not notice them.
Avoid it: After parentheses, always look for exponents next.
- 03
Doing division before multiplication, or vice versa, not left to right
Why: Students might think multiplication always comes before division.
Avoid it: Do multiplication and division as you see them, moving left to right.
Practice
Answers stay hidden
1.4 + 2^2 × (6 - 1) ÷ 5
Show hint
Follow PEMDAS. Start with the parentheses, then exponents.
Reveal answer
6
2.7 + 3^2 × (5 + 1) ÷ 2
Show hint
Work inside the parentheses first.
Reveal answer
34
3.2 + 5^2 × (9 - 4) ÷ 5
Show hint
Calculate the exponent before multiplying.
Reveal answer
27