Printable Percent Increase Word Problems for 7th Grade Math

📚 Understanding Percent Increase

Percent increase is a way to describe how much a quantity has grown. It's used everywhere from calculating sales tax to figuring out investment returns. Essentially, it's the percentage by which an original amount has increased.

📜 History and Background

The concept of percentages has been around for centuries, dating back to ancient Rome. However, the formal use of percent increase in mathematical and financial calculations became more prevalent during the Renaissance. As trade and commerce expanded, the need to quantify growth and change became essential.

🔑 Key Principles

• 🧮 Original Amount: This is the starting value.
• ➕ New Amount: This is the value after the increase.
• ➗ Amount of Increase: Calculated by subtracting the original amount from the new amount.
• 📊 Percent Increase Formula: $\text{Percent Increase} = \frac{\text{Amount of Increase}}{\text{Original Amount}} \times 100$

📈 Real-World Examples

Let's look at some examples to make it clearer:

1. Example 1:

   A store bought a video game for $40 and sells it for $60. What is the percent increase?

   Amount of Increase = $60 - $40 = $20

   Percent Increase = $\frac{20}{40} \times 100 = 50\%$

2. Example 2:

   A plant grew from 10 inches to 15 inches. What is the percent increase in height?

   Amount of Increase = 15 - 10 = 5 inches

   Percent Increase = $\frac{5}{10} \times 100 = 50\%$

3. Example 3:

   The price of gas increased from $3.00 to $3.60. What is the percent increase?

   Amount of Increase = $3.60 - $3.00 = $0.60

   Percent Increase = $\frac{0.60}{3.00} \times 100 = 20\%$

✍️ Practice Quiz

1. A toy originally priced at $20 is now sold for $25. Calculate the percent increase.

2. A company's profit rose from $50,000 to $60,000. What is the percent increase in profit?

3. The number of students in a class increased from 25 to 30. Find the percent increase.

4. Sarah's salary increased from $40,000 to $44,000. What is the percent increase in her salary?

5. The price of a book increased from $10 to $12. Calculate the percent increase.

6. A store increased the price of a shirt from $15 to $18. What is the percent increase?

7. The population of a town increased from 1,000 to 1,100. Calculate the percent increase.

✅ Solutions to Practice Quiz

1. Percent Increase = $\frac{25-20}{20} \times 100 = 25\%$

2. Percent Increase = $\frac{60000-50000}{50000} \times 100 = 20\%$

3. Percent Increase = $\frac{30-25}{25} \times 100 = 20\%$

4. Percent Increase = $\frac{44000-40000}{40000} \times 100 = 10\%$

5. Percent Increase = $\frac{12-10}{10} \times 100 = 20\%$

6. Percent Increase = $\frac{18-15}{15} \times 100 = 20\%$

7. Percent Increase = $\frac{1100-1000}{1000} \times 100 = 10\%$

🎯 Conclusion

Understanding percent increase is crucial for various real-world applications. By mastering the formula and practicing with different examples, you can confidently solve percent increase problems. Keep practicing, and you'll become a pro in no time!