Finding a Percent of a Number
Finding a percent of a number in Grade 8 Saxon Math Course 3 involves converting the percent to a decimal or fraction and multiplying by the given number. Students use this skill in discount, tax, tip, interest, and commission problems, making it one of the most practically important math skills in the curriculum. Understanding this operation builds a foundation for financial literacy and data analysis.
Key Concepts
Property To find a percent of a number we change the percent to a decimal or fraction and then multiply. The word 'of' in mathematics usually means to multiply.
Examples To find $80\%$ of 40 dollars, convert to a decimal: $0.80 \times 40 = 32$ dollars. To find $75\%$ of 40 dollars, convert to a fraction: $\tfrac{3}{4} \times 40 = 30$ dollars. To estimate $8\%$ sales tax on 20 dollars: $0.08 \times 20 = 1.60$ dollars.
Explanation Finding a percentage is like grabbing a specific slice of a whole pie. First, you must convert your percent into a more math friendly form—either a decimal (by moving the decimal point two spots left) or a fraction. The word 'of' is your secret code word for 'multiply.' So, just multiply your new decimal or fraction by the total number to find your answer!
Common Questions
How do you find a percent of a number?
Convert the percent to a decimal by dividing by 100, then multiply by the number. For example, 30% of 80 = 0.30 x 80 = 24.
How do you find 15% of 60?
15% = 0.15. 0.15 x 60 = 9. Fifteen percent of 60 is 9.
How can you find a percent of a number using fractions?
Convert the percent to a fraction. For example, 25% = 1/4. Then multiply: 1/4 x 40 = 10. Twenty-five percent of 40 is 10.
How is finding a percent of a number used in real life?
Used to calculate sales tax (rate x purchase price), tips (percent x bill total), discounts (percent x original price), and interest (rate x principal).
How does Saxon Math Course 3 teach finding a percent of a number?
Saxon Math Course 3 practices this skill through diverse word problems involving money, data, and science, using both decimal and fraction methods to reinforce the concept from multiple angles.