University:
Nevada State University
Course:
EDRL 474 | Methods for English Language Learners
Academic year:

2024
Views:

185

Pages:

3
Author:

Chloe F.

Understanding Percentages 1. Definition: A percentage is a fraction or ratio expressed as part of 100. It is denoted using the percent symbol (%). Example: 45% means 45 out of 100, or 45/100. 2. Converting Fractions and Decimals to Percentages: Fraction to Percentage: Multiply the fraction by 100 and add the % symbol. Example: 3/4 → 3/4×100=75% Decimal to Percentage: Multiply the decimal by 100 and add the % symbol. Example: 0.65 → 0.65×100=65% 3. Converting Percentages to Fractions and Decimals: Percentage to Fraction: Divide by 100 and simplify if possible. Example: 75% → 75/100=¾ Percentage to Decimal: Divide by 100. Example: 65% → 65/100=0.65 Calculating Percentages 1. Finding a Percentage of a Number: Formula: Part=Percentage/100×Whole Example: What is 20% of 150? Calculation: 20/100×150=30 2. Finding the Whole from a Percentage: Formula: Whole=Part/Percentage×100 Example: If 30 is 20% of a number, what is the number? Calculation: 30/20×100=150 3. Finding What Percentage One Number is of Another: Formula: Percentage=Part/Whole×100 Example: What percentage of 200 is 50? Calculation: 50/200×100=25% Percentage Increase and Decrease 1. Percentage Increase: Formula:Percentage Increase=New Value−Original Value/Original Value×100 Example: If a price increases from $50 to $60: Calculation: 60−50/50×100=20% 2. Percentage Decrease: Formula:Percentage Decrease=Original Value−New ValueOriginal Value×100 Example: If a price decreases from $80 to $60: Calculation: 80−60/80×100=25% Applications of Percentages 1. Discounts: Calculating the sale price after a discount. Example: An item priced at $120 with a 25% discount. Calculation: Discount amount = 25/100×120=30 Sale price = 120−30=90 2. Taxes: Adding tax to the original price. Example: An item priced at $200 with an 8% tax. Calculation: Tax amount = 8/100×200=16 Total price = 200+16=216 3. Interest Rates: Calculating simple interest. Formula: Simple Interest=Principal×Rate×Time Example: Principal of $1000, rate of 5% per year, for 3 years. Calculation: 1000×0.05×3=150 Tips for Working with Percentages  Always convert percentages to decimals or fractions when performing calculations.  Double-check your conversions to ensure accuracy.  Practice word problems to gain proficiency in identifying what each percentage represents in different contexts.