Understanding Order of Operations in Math

Sep 9, 2024

Math Antics: Order of Operations

Introduction

  • Order of Operations: A set of rules that dictate the sequence to perform math operations (addition, multiplication, etc.) to ensure consistency in solving problems.
  • Importance: Without these rules, the same mathematical expression could yield different answers based on the sequence of operations chosen.

Why Order Matters

  • Example Problem: 2 + 5 × 4
    • Different sequences:
      • Addition first: (2 + 5) × 4 = 28
      • Multiplication first: 5 × 4 + 2 = 22 (Correct Answer)
  • Conclusion: Performing operations in different orders can lead to different results.

The Rules of Order of Operations

  1. Parentheses and Brackets

    • Always perform operations inside parentheses/brackets first.
    • Example: 10 × (4 + 5)
      • Inside parentheses first: 4 + 5 = 9
      • Then multiply: 10 × 9 = 90
    • Multiple parentheses: Simplify each set before dealing with anything outside.
  2. Exponents

    • Perform any exponentiation following parentheses.
    • Example: 5² × 3
      • Simplify exponent: 5 × 5 = 25
      • Then multiply by 3: 25 × 3 = 75
  3. Multiplication and Division

    • Perform these operations from left to right after exponents.
    • Examples:
      • 3 × 5 − 1
        • Multiply first: 3 × 5 = 15
        • Then subtract: 15 − 1 = 14
      • 20 − 10 ÷ 5
        • Divide first: 10 ÷ 5 = 2
        • Then subtract: 20 − 2 = 18
  4. Addition and Subtraction

    • Perform these operations last, from left to right.
    • Example: 12 ÷ 6 + 5
      • Divide first: 12 ÷ 6 = 2
      • Then add: 2 + 5 = 7

Tied Operations

  • Multiplication and Division, Addition and Subtraction have equal priority.
  • Perform these operations in order from left to right to ensure consistent results.
    • Example: 40 ÷ 4 × 5
      • Correct: 40 ÷ 4 = 10, then 10 × 5 = 50

Summary of Order of Operations

  1. Parentheses and Brackets
  2. Exponents
  3. Multiplication and Division (left to right)
  4. Addition and Subtraction (left to right)

Conclusion

  • Understanding and applying these rules ensures consistency and correctness in mathematical problem-solving.
  • Practice with exercises to get comfortable with applying these rules.

Learn more at Math Antics