Expressing Ratio as Percent
Learning how to express one number as a percent of another is a powerful skill that helps us compare quantities, understand statistics, and solve real-world problems!
What Does It Mean?
When we express a ratio as a percent, we're answering the question:
"What percent is one number of another?"
For example: "What percent is 15 of 60?"
We're comparing two quantities and expressing their relationship using percent (out of 100).
Answer: 15 is 25% of 60
Key Vocabulary
| Term | Meaning |
|---|---|
| Part | The number being compared |
| Whole | The number we compare TO (usually after "of") |
| Percent | The ratio expressed out of 100 |
| Ratio | Comparison of two quantities |
Tip: The word after "of" is usually the WHOLE!
The Main Formula
Percent = (Part ÷ Whole) × 100%
Or, equivalently, written as a fraction:
$$\text{Percent} = \frac{\text{Part}}{\text{Whole}} \times 100\%$$
Interactive visualization — available in the full lesson