SECTION 1
Why We Need Order of Operations
Imagine playing a game where everyone follows different rules. That would be confusing! Long ago, mathematicians faced the same problem with expressions like 2 + 3 × 4. Without clear rules, one person might get 20, and another 14. The order of operations fixes this by giving steps to follow. It started in the 1600s when people like Descartes wrote math books.
1637 • Descartes' Book
1800s • Math Textbooks
1900s • PEMDAS Mnemonic
Today • SSAT Tests
These rules solve the big question: How do we agree on expression values? Now you can too!
SECTION 2
Core Principles of Order of Operations
The order of operations is a set of rules. It tells you the right sequence for math. Think of it like steps in a video game level.
Parentheses First
Exponents Next
Multiply & Divide
Add & Subtract Last
PEMDAS Mnemonic
KEY TAKEAWAY
SECTION 3
Visualizing the Order
See the pyramid above? It shows how to climb from top to bottom. Parentheses are always first. This visual makes PEMDAS easy to remember!
SECTION 4
How It Works: The Rules in Action
Use PEMDAS every time. Start with parentheses, then exponents, and so on. Let's see examples.
PEMDAS RULE
MD means multiply or divide. AS means add or subtract.
EXAMPLE
Exponents first (2²=4), then × (3×4=12), then +.
Always go left to right for same-level steps. You are building math superpowers!
SECTION 5
Step-by-Step Breakdown
The tree above breaks down 2 + 5 × (3 + 1)² − 4. Each branch is one step. Follow it like a treasure map!
SECTION 6
Worked Example
Evaluate 10 − 2 × 3 + 4²
- 1
Step 1: Parentheses
No parentheses. Go to exponents.10 − 2 × 3 + 4² - 2
Step 2: Exponents
4² = 16.10 − 2 × 3 + 16 - 3
Step 3: Multiply/Divide left to right
2 × 3 = 6.10 − 6 + 16 - 4
Step 4: Add/Subtract left to right
10 − 6 = 4, then 4 + 16 = 20.20
Tip
SECTION 7
Strengths and Common Errors
Order of operations makes math fair. But watch for traps like forgetting left-to-right.
| Correct Way | Common Mistake | Why Wrong? |
|---|---|---|
| 3 + 2 × 4 = 11 | Do + first = 20 | × before +! |
| 12 ÷ 3 × 2 = 8 | ÷ first only = 4 | Left to right for same level. |
Avoid these to score high on SSAT!
Key takeaway
SECTION 8
To Algebra and Beyond
PEMDAS works with variables too, like x + 2y. It leads to harder SSAT problems.
| Basic PEMDAS | Advanced Version |
|---|---|
| Numbers only | Variables, fractions |
| 5 + 3 × 2 | (x + 1)² / 2 − y |
Master this now for algebra later. You're on the path to acing upper levels!
SECTION 9
Practice Problems
Question 1: CONCEPTUAL
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Question 2: BASIC CALCULATION
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Question 3: INTERMEDIATE
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Question 4: APPLIED
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Question 5: CRITICAL THINKING
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SUMMARY
Lesson Summary
Summary
Master PEMDAS: Parentheses, Exponents, Mult/Div left-right, Add/Sub left-right. Use diagrams and steps.
Practice makes you fast for SSAT. Believe in yourself—you just leveled up math skills!