Basic Math

Fundamental mathematical operations and concepts for everyday use.

Advanced Topics

Decimals and Percentages

Going Beyond Whole Numbers

Decimals and percentages are ways to show numbers smaller than one or parts of a whole.

Decimals

Decimals use a dot (.) to separate the whole number from the part.

  • 0.5 is half, just like \( \frac{1}{2} \).
  • 2.75 means 2 whole and 75 hundredths.

Percentages

Percentages are fractions out of 100. The symbol "%" means "per hundred."

  • 25% means 25 out of 100, or \( \frac{25}{100} \).

Everyday Uses

You see decimals in money ($3.50) and percentages in sales (20% off) all the time!

Examples

  • Paying $1.99 for a snack at the store.

  • Getting 80% correct on a quiz.

In a Nutshell

Decimals and percentages help express parts of a whole in a different way.

Key Terms

Decimal
A number that shows values less than one using a dot.
Percent
A way to express a number as parts out of 100.