Identifying Relevant Facts

Oct 13, 2025 by wbrum.org 32 views

Introduction

Percentages are a fundamental concept in mathematics, and understanding how to calculate them is crucial for various real-world applications. In this article, we will delve into the world of percentages and explore how to calculate them using simple arithmetic operations. We will also discuss the importance of identifying relevant facts that can help complete calculations.

What are Percentages?

Percentages are a way to express a value as a fraction of 100. For example, 25% is equivalent to 25/100 or 0.25. Percentages are often used to represent a proportion or a part of a whole. In the given problem, we are asked to find 21% of 90.

Calculating Percentages

To calculate a percentage, we need to multiply the value by the percentage as a decimal. In this case, we need to find 21% of 90. To do this, we can convert 21% to a decimal by dividing it by 100. This gives us 0.21. We can then multiply 90 by 0.21 to get the result.

Identifying Relevant Facts

The problem provides us with three facts: A, B, and C. We need to circle the two facts that could help us complete the calculation. Let's analyze each fact:

Fact A: $90 \div 10 = 9$
Fact B: $50\% \text{ of } 90 = 45$
Fact C: $9 \div 10 = 0.9$

Fact A: $90 \div 10 = 9$

Fact A is a simple division problem. However, it does not directly help us calculate 21% of 90. We can use this fact to find 10% of 90 by dividing 90 by 10, but we need to find 21% of 90.

Fact B: $50\% \text{ of } 90 = 45$

Fact B is a percentage calculation. We can use this fact to find 50% of 90, which is 45. However, we need to find 21% of 90, not 50%.

Fact C: $9 \div 10 = 0.9$

Fact C is a division problem. We can use this fact to find 10% of 9, which is 0.9. However, we need to find 21% of 90, not 10% of 9.

Conclusion

In conclusion, we need to find two facts that can help us complete the calculation. Fact A and Fact C are not directly relevant to the calculation. However, Fact B is a percentage calculation that can help us find 50% of 90, which is 45. We can use this fact to find 21% of 90 by multiplying 45 by 0.42 (21/50). This gives us 18.9, which is close to the actual result.

The Importance of Identifying Relevant Facts

Identifying relevant facts is crucial for completing calculations. In this problem, we need to find two facts that can help us complete the calculation. Fact B is a percentage calculation that can help us find 50% of 90, which is 45. We can use this fact to find 21% of 90 by multiplying 45 by 0.42 (21/50). This gives us 18.9, which is close to the actual result.

Real-World Applications

Understanding percentages and calculations is crucial for various real-world applications. In finance, percentages are used to calculate interest rates, investment returns, and inflation rates. In science, percentages are used to calculate concentrations, proportions, and rates of change. In everyday life, percentages are used to calculate discounts, tips, and sales tax.

Conclusion

In conclusion, understanding percentages and calculations is crucial for various real-world applications. Identifying relevant facts is essential for completing calculations. By analyzing the given facts and using relevant calculations, we can complete the calculation and find the result.

Final Answer

The final answer is not provided in the problem. However, we can use the fact that 21% of 90 is equal to 0.21 x 90 = 18.9.

References

Khan Academy. (n.d.). Percentages. Retrieved from <https://www.khanacademy.org/math/algebra/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6
Q&A: Understanding Percentages and Calculations =====================================================

Introduction

Understanding percentages and calculations is crucial for various real-world applications. In this article, we will answer some frequently asked questions related to percentages and calculations.

Q: What is a percentage?

A: A percentage is a way to express a value as a fraction of 100. For example, 25% is equivalent to 25/100 or 0.25.

Q: How do I calculate a percentage?

A: To calculate a percentage, you need to multiply the value by the percentage as a decimal. For example, to find 21% of 90, you can multiply 90 by 0.21.

Q: What is the difference between a percentage and a decimal?

A: A percentage is a way to express a value as a fraction of 100, while a decimal is a way to express a value as a fraction with a denominator of 10. For example, 25% is equivalent to 0.25.

Q: How do I convert a percentage to a decimal?

A: To convert a percentage to a decimal, you need to divide the percentage by 100. For example, to convert 21% to a decimal, you can divide 21 by 100, which gives you 0.21.

Q: What is the importance of identifying relevant facts in calculations?

A: Identifying relevant facts is crucial for completing calculations. In the given problem, we need to find two facts that can help us complete the calculation. Fact B is a percentage calculation that can help us find 50% of 90, which is 45. We can use this fact to find 21% of 90 by multiplying 45 by 0.42 (21/50).

Q: How do I use percentages in real-world applications?

A: Percentages are used in various real-world applications, such as finance, science, and everyday life. In finance, percentages are used to calculate interest rates, investment returns, and inflation rates. In science, percentages are used to calculate concentrations, proportions, and rates of change. In everyday life, percentages are used to calculate discounts, tips, and sales tax.

Q: What are some common mistakes to avoid when working with percentages?

A: Some common mistakes to avoid when working with percentages include:

Not converting percentages to decimals before performing calculations
Not identifying relevant facts that can help complete calculations
Not using the correct formula for calculating percentages
Not checking units and making sure they are consistent

Conclusion

In conclusion, understanding percentages and calculations is crucial for various real-world applications. By answering these frequently asked questions, we hope to provide a better understanding of percentages and calculations.

Final Answer

The final answer is not provided in the problem. However, we can use the fact that 21% of 90 is equal to 0.21 x 90 = 18.9.

References

Khan Academy. (n.d.). Percentages. Retrieved from <https://www.khanacademy.org/math/algebra/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2f6f7c/x2