Real-world examples of function tables for 8th graders

📚 Quick Study Guide

• 🔢 A function table shows the relationship between an input ($x$) and an output ($y$).
• 📝 Each input has exactly one output.
• 📈 The general form is often represented as $y = f(x)$, where $f$ is the function.
• 💡 Function tables can be used to represent various real-world scenarios like currency conversion or calculating distances.
• ➕ To use a function table, substitute the input ($x$) into the function to determine the output ($y$).

🧪 Practice Quiz

1. What real-world scenario can be modeled using the function $y = 2.54x$, where $x$ is inches and $y$ is centimeters?
   1. A) Converting Celsius to Fahrenheit
   2. B) Converting inches to centimeters
   3. C) Converting kilograms to pounds
   4. D) Converting liters to gallons
2. A taxi service charges a flat fee of $5 plus $2 per mile. Which function table correctly represents the total cost ($y$) for different distances ($x$ miles)?
   1. A) $y = 5x + 2$
   2. B) $y = 2x + 5$
   3. C) $y = 7x$
   4. D) $y = 3x + 5$
3. If a vending machine charges $1.50 per snack, what function could represent the total cost ($y$) for buying $x$ snacks?
   1. A) $y = x + 1.50$
   2. B) $y = 1.50x$
   3. C) $y = x - 1.50$
   4. D) $y = \frac{x}{1.50}$
4. A phone company charges a monthly fee of $20 plus $0.10 per minute of talk time. Which equation represents the total monthly bill ($y$) for $x$ minutes?
   1. A) $y = 0.10x - 20$
   2. B) $y = 20x + 0.10$
   3. C) $y = 0.10x + 20$
   4. D) $y = 20 - 0.10x$
5. A bakery sells cookies for $2 each. They have a fixed daily cost of $50 for ingredients and rent. Which function best represents the daily profit ($y$) if they sell $x$ cookies?
   1. A) $y = 50 - 2x$
   2. B) $y = 2x + 50$
   3. C) $y = 2x - 50$
   4. D) $y = 50x - 2$
6. A car travels at a constant speed of 60 miles per hour. Which function represents the distance ($y$) traveled in $x$ hours?
   1. A) $y = x + 60$
   2. B) $y = \frac{x}{60}$
   3. C) $y = 60x$
   4. D) $y = 60 + x^2$
7. A store offers a 10% discount on all items. If the original price of an item is $x$, which function represents the discounted price ($y$)?
   1. A) $y = 0.10x$
   2. B) $y = x + 0.10x$
   3. C) $y = x - 0.10x$
   4. D) $y = 1.10x$