Order of Operations
This is the set of rules that tells us the correct sequence to solve a math problem with multiple operations (like +, -, ×, ÷). Without these rules, everyone could get a different answer for the same problem!
How to Solve: PEMDAS
Remember the acronym PEMDAS to know what order to follow:
- Parentheses - Do everything inside parentheses first.
- Exponents - Solve any exponents (like 3²).
- Multiplication and Division - Do these from left to right.
- Addition and Subtraction - Do these from left to right.
Worked Examples
Example 1: 12 ÷ 3 × 2 + (5 - 2)
- Parentheses: (5 - 2) = 3 → Now we have: 12 ÷ 3 × 2 + 3
- Division/Multiplication (left to right): 12 ÷ 3 = 4 → 4 × 2 = 8 → Now we have: 8 + 3
- Addition: 8 + 3 = 11 ✅
Example 2: 5 + 2 × 3²
- Exponents: 3² = 9 → Now we have: 5 + 2 × 9
- Multiplication: 2 × 9 = 18 → Now we have: 5 + 18
- Addition: 5 + 18 = 23 ✅
⚠️ Common Mistakes
- Going left to right without PEMDAS: For 10 - 3 + 2, you do go left to right (7 + 2 = 9). But for 10 - 3 × 2, multiplication comes first! (3 × 2 = 6, then 10 - 6 = 4).
- Thinking "M" always comes before "D": Multiplication and Division have equal priority, so you solve them from left to right. 8 ÷ 4 × 2 = 2 × 2 = 4 (not 8 ÷ 8 = 1).
🎯 Tips & Tricks
- Remember PEMDAS as: "Please Excuse My Dear Aunt Sally"
- Underline or highlight the operation you are about to do next in the problem.
- Rewrite the problem after each step so you don't get lost.
How to Practice
Try creating your own problems! Start simple like 4 × (2 + 5). Then, make them more complex. Ask a friend to solve it and see if you get the same answer. You can also find lots of practice worksheets online. ✏️