Overview
This lecture explains how to convert between decimals and percentages using simple multiplication or division by 100.
Converting Decimals to Percentages
- To convert a decimal to a percentage, multiply the decimal by 100.
- Example: 0.45 × 100 = 45%
- You can multiply by 10 twice for easier calculation (e.g., 0.45 × 10 = 4.5, then 4.5 × 10 = 45%).
Converting Percentages to Decimals
- To convert a percentage to a decimal, divide the percentage by 100.
- Example: 28 ÷ 100 = 0.28
- You can divide by 10 twice for easier calculation (e.g., 28 ÷ 10 = 2.8, then 2.8 ÷ 10 = 0.28).
Additional Examples
- 0.073 as a percentage: 0.073 × 100 = 7.3%
- 142% as a decimal: 142 ÷ 100 = 1.42
- If the percentage is over 100%, the decimal will be greater than 1.
Key Terms & Definitions
- Percentage — a number expressed as a fraction of 100 (e.g., 45% means 45 out of 100).
- Decimal — a number that uses a decimal point to represent a fraction (e.g., 0.45).
Action Items / Next Steps
- Practice converting between decimals and percentages using various numbers.
- Review any textbook examples or assigned practice problems on this topic.