Significant figures are the number of digits in a value, often a measurement, that contribute to the degree of accuracy of the value.
Significant figures are important to show the precision of your answer.
Formula to express a number in significant figures.
- For a number without a decimal, you start counting for significant figures on the first non-zero digit from your left.
- Zeroes in between two non-zero digits are significant.
- All non-zero digits are significant.
- Right-end zeros in a number with a decimal point are significant.
Example:
Express 45 to 4 significant figures.
To express 45 to 4 significant figures we will need to put a decimal after 5 and then add two zeros as we have been told that the right-end zeros in a number with a decimal point are significant.
Therefore, we will have 45.00.
