Counting the 110. sig fig
The number 110. (with a trailing decimal point) contains three significant figures. The decimal point communicates that the measurement is written to the ones place, so the trailing zero is intentional and significant.
Step-by-step reasoning
- Identify the digits: 1, 1, and 0.
- Apply the nonzero-digit rule: all nonzero digits are significant, so both 1s are significant.
- Apply the trailing-zero rule using the decimal point: in 110., the decimal point indicates the zero is a measured (reported) digit, so the 0 is significant.
- Count significant digits: \(2 + 1 = 3\), so 110. has \(3\) significant figures.
Scientific notation check
Writing 110. in scientific notation makes the significance explicit: \[110. = 1.10 \times 10^2\] The coefficient 1.10 shows three significant digits (the trailing zero after the decimal is significant).
Common related cases
| Number | Significant figures | Reason (sig fig rule) |
|---|---|---|
| 110. | 3 | Decimal point indicates the trailing zero is significant. |
| 110 | Usually 2 (context-dependent) | Trailing zero without a decimal point is commonly treated as not significant unless specified. |
| 110.0 | 4 | All digits including the trailing zero after the decimal are significant. |
| 0.0110 | 3 | Leading zeros are not significant; the trailing zero after the decimal is significant. |
| \(1.10 \times 10^2\) | 3 | Scientific notation explicitly shows the significant digits in the coefficient. |
Conclusion
For significant figures (sig figs), 110. has three significant figures because the decimal point indicates that the trailing zero is a meaningful, measured digit rather than a placeholder.