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What Is the Order of Operations (PEMDAS)?

2 min read4th6th

The order of operations is the set of rules that determines which calculations to perform first in a math expression.

Without these rules, 3 + 4 × 2 could be 14 (add first) or 11 (multiply first). The order of operations says: multiply first. The answer is 11.

The rules (PEMDAS)

  1. Parentheses — do what is inside parentheses first
  2. Exponents — calculate powers and roots
  3. Multiplication and Division — left to right (equal priority)
  4. Addition and Subtraction — left to right (equal priority)

Important: Multiplication and division have the same priority — work left to right. Same for addition and subtraction.

Example

Solve: 2 + 3 × (4 + 1)² ÷ 5

  1. Parentheses: (4 + 1) = 5 → 2 + 3 × 5² ÷ 5
  2. Exponents: 5² = 25 → 2 + 3 × 25 ÷ 5
  3. Multiplication/Division (left to right): 3 × 25 = 75, then 75 ÷ 5 = 15 → 2 + 15
  4. Addition: 2 + 15 = 17

Common mistakes

Doing addition before multiplication: 3 + 4 × 2 = 14 is wrong. Multiply first: 3 + 8 = 11.

Always doing multiplication before division: They are equal priority. 12 ÷ 3 × 2 = 8 (left to right), not 12 ÷ 6 = 2.

Thinking PEMDAS means M always comes before D: The M and D are worked left to right, as are A and S.

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