# Answering Numerical Questions That Check Significant Figures

Numerical questions that check significant figures require you both to calculate the
correct answer and to specify that answer using the correct number of significant digits,
for example, `2.3e4` to indicate 2 significant digits. The kind of
answer that is expected should be clear from the question.

If your instructor has enabled it, the sigfig icon is displayed beside the answer box for questions that check for significant figures.

If enabled by your instructor, an answer format tip is displayed below the answer box when it is selected and provides information about the form of the answer that is expected. The answer format tip indicates that a number must specified to the correct number of significant figures, and might also specify whether units are required.

If the question checks for significant figures, type a number with the correct number of significant figures for your answer. The rules WebAssign uses to specify the number of significant figures in a number are standard. They are shown in the examples below:

Rule |
Example |
Significant Figures |
---|---|---|

Every non-zero digit is significant. |
1234 |
4 |

Zeros in between non-zero digits are significant. |
101.001 41003 |
6 5 |

Zeros at the end of the answer when |
500 13000 140e-001 |
1 2 2 |

Zeros at the end of the answer when a decimal point |
500. 5.0e2 2.000 8.20000e3 |
3 2 4 6 |

- To express a number like 1000 to 2 or 3 significant figures, you must use scientific notation, for example, 1.0e3 or 1.00e3.
- When entering scientific notation, always use a lowercase
`e`and an integer exponent, for example, 1.23e-5. - Commas are not allowed when significant figures are checked.
- If you are not sure how to determine the correct number of significant figures for a problem, refer to your textbook or ask your instructor.

If it is displayed, you can click the sigfig icon to list the rules used for significant figures in WebAssign.