| Rule | Example | Sig Figs |
|---|---|---|
| Non-zero digits | 1234 | 4 |
| Leading zeros | 0.0045 | 2 |
| Captive zeros | 1005 | 4 |
| Trailing zeros (after decimal) | 45.00 | 4 |
| Trailing zeros (no decimal) | 1500 | 2 (ambiguous) |
Significant figures indicate the precision of a measurement. When performing calculations, the result should reflect the precision of the least precise input.
Round to the least precise decimal place. For example: 12.11 + 3.2 = 15.31 → 15.3 (round to tenths)
Round to the least number of significant figures. For example: 4.56 × 1.4 = 6.38 → 6.4 (2 sig figs)