Basic Concepts
In a nutshell: Switch easily between fractions, decimals, and percents to solve real-world problems.
## Mastering Parts of a Whole
Fractions, decimals, and percents are just different ways of showing parts of something. Mastering how to switch between them is useful for shopping, sports, and more!
### Fractions
Fractions show how much of something you have: \( \frac{3}{4} \) of a pizza.
### Decimals
Decimals are another way to show parts, like 0.75 instead of \( \frac{3}{4} \).
### Percents
Percents mean “out of 100.” So 75% is the same as 0.75 or \( \frac{3}{4} \).
### Conversions
- Fraction to decimal: Divide the top by the bottom.
- Decimal to percent: Multiply by 100 and add the % sign.
- Percent to fraction: Write over 100 and simplify.
### Why It’s Useful
Discounts, test scores, and recipes all use fractions, decimals, or percents.
Examples
- Scoring 18 out of 20 on a quiz is \( \frac{18}{20} = 0.9 = 90\% \).
- A 25% off sale means you pay only 75% of the price.
Key terms
- Percent
- A ratio out of 100, shown with the % symbol.
- Decimal
- A way to write fractions using place value and a decimal point.
- Fraction
- A way to show part of a whole, with a numerator and denominator.