Lesson 1.1: Understanding Ratios
Learn how to compare two quantities using ratios.
Example: If there are 2 apples for every 3 oranges, the ratio is 2:3.
If a recipe calls for 4 cups of flour and 6 cups of sugar, what is the ratio of flour to sugar?
How to get the right answer:
Divide both numbers by their **greatest common factor (GCF)**.
GCF of 4 and 6 is **2**, so 4:6 simplifies to **2:3**.
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Lesson 1.2: Proportions and Equivalent Ratios
Learn how to set up and solve proportions using equivalent ratios.
Example: If 3 pencils cost $6, how much do 9 pencils cost?
If 5 notebooks cost $15, how much do 10 notebooks cost?
How to get the right answer:
Set up the proportion:
**5/15 = 10/x** → Cross-multiply: **5x = 150** → Solve: **x = 30**.
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Lesson 1.3: Scale Drawings
Learn how to interpret and create scale drawings using proportions.
Example: A map shows 1 inch = 5 miles. How far is a 3-inch distance?
If a blueprint has a scale of 1 inch = 4 feet, how long is a 5-inch line?
How to get the right answer:
Multiply the scale by the given measurement:
**5 inches × 4 feet = 20 feet.**
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