| English | Significant figures |
|---|---|
| Bahasa Melayu | Angka bererti |
| 中文 | 有效数字 |
Definition
The digits in a measurement that carry meaningful information about its precision.
In exam terms
Significant figures are the digits in a measurement that carry meaningful information about how precisely it was measured. They include all non-zero digits, any zeros between them, and trailing zeros in a decimal number.
For example, 0.00450 m has three significant figures (4, 5 and the final 0). The number of significant figures should match the precision of the instrument used.
In calculations, the answer is usually given to the same number of significant figures as the least precise measurement. A correct sentence: The reading 2.30 A is stated to three significant figures.
Do not confuse it with decimal places
Do not confuse significant figures with decimal places. The number 0.0250 has three significant figures but four decimal places, so the two counts can differ.
In Paper 2, a numerical answer that is not rounded to a sensible number of significant figures can lose a mark, and rounding too early causes errors. Keep extra digits during working and round only the final answer.
If asked to give an answer to 3 significant figures, count from the first non-zero digit.
Source: DSKP KSSM Physics Form 4 and 5 (Versi English) (Bahagian Pembangunan Kurikulum (BPK), KPM)