What Is Scientific Notation?
Scientific notation writes numbers as:
a × 10ⁿ where 1 ≤ a < 10
It separates the significant digits (a) from the magnitude (10ⁿ).
Examples
| Standard Form | Scientific Notation |
|---|---|
| 4,500,000 | 4.5 × 10⁶ |
| 320 | 3.2 × 10² |
| 0.00067 | 6.7 × 10⁻⁴ |
| 93,000,000 | 9.3 × 10⁷ |
How it works
Large numbers have positive exponents. The exponent tells you how many places the decimal moved left.
- 4,500,000 → 4.5 (decimal moved 6 places left) → 4.5 × 10⁶
Small numbers have negative exponents. The exponent tells you how many places the decimal moved right.
- 0.00067 → 6.7 (decimal moved 4 places right) → 6.7 × 10⁻⁴
Why it is used
Numbers like 149,600,000,000 (Earth-Sun distance in meters) or 0.000000001 (size of a molecule in meters) are impractical to write or read. Scientific notation makes them manageable: 1.496 × 10¹¹ and 1 × 10⁻⁹.
Related concepts
- How to Teach Scientific Notation: full teaching guide
- Exponents: the powers of 10 used in scientific notation
- Place value: scientific notation is built on place value