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Dino Math Adventure

Pre-Algebra · Grades 4–5 · 20 Questions

Join Rex the Dino on a math adventure through the Jurassic jungle! Master the key concepts of pre-algebra and earn your Dino Math Badge! 🏅

🗺️ Topics Covered Today

➕Order of Operations

½Fractions

💧Decimals

%Percentages

⚖️Ratios & Proportions

🔣Variables & Equations

📐Geometry Basics

🔢Integers & Sequences

🧠 Key Formulas — Memorize These!

🦖 PEMDAS (Order of Operations)
Parentheses → Exponents → Multiply/Divide → Add/Subtract
Always work left to right within the same level.

½ Fractions
Add/Subtract: find LCD first
Multiply: top × top, bottom × bottom
Divide: Keep, Change, Flip (KCF)

% Percent
% of a number = (percent ÷ 100) × whole
Example: 30% of 80 = 0.30 × 80 = 24

⚖️ Ratio & Proportion
Simplify ratios like fractions. In a proportion:
a/b = c/d → cross multiply → a×d = b×c

🔣 Equations
Use inverse operations to isolate the variable.
x + 7 = 15 → x = 15 - 7 = 8
3x = 24 → x = 24 ÷ 3 = 8

📐 Geometry
Area of rectangle = length × width
Perimeter = 2 × (length + width)

🔢 Integers
negative × negative = positive
negative × positive = negative
negative ÷ positive = negative

🗺️ Coordinate Plane Quadrants
Q I: (+, +) · Q II: (−, +) · Q III: (−, −) · Q IV: (+, −)

📖 Worked Examples

🦕 Example 1 — Order of Operations

Solve: 3 + 4 × 2 − 1

Step 1: Multiply first → 4 × 2 = 8
Step 2: Left to right → 3 + 8 − 1 = 10

Answer: 10

🦖 Example 2 — Adding Fractions

Solve: 1/3 + 1/4

Step 1: LCD of 3 and 4 = 12
Step 2: 1/3 = 4/12, 1/4 = 3/12
Step 3: 4/12 + 3/12 = 7/12

Answer: 7/12

🦕 Example 3 — Solving an Equation

Solve: 2x − 5 = 11

Step 1: Add 5 to both sides → 2x = 16
Step 2: Divide both sides by 2 → x = 8

Answer: x = 8