Significant figures

Definition:

• Significant figures are the digits in a measurement that carry meaning and contribute to its precision. They include all known digits plus one estimated digit.

Rules for Significant Figures:

1. All non-zero digits are significant.

2. Any zeros between significant digits are significant.

3. Leading zeros (zeros to the left of the first non-zero digit) are not significant.

4. Trailing zeros in a decimal number are significant, but trailing zeros in a whole number without a decimal may or may not be significant, depending on the context.

Example:

• 123.45 has 5 significant figures.

• 0.00456 has 3 significant figures (the zeros are not significant).

• 4500 has 2 significant figures (unless a decimal is added, e.g., 4500.0 has 5 significant figures).

Explanation:

• Significant figures are important in ensuring that measurements and calculations are not over-represented with more precision than the data supports.

• When performing calculations (addition, multiplication, etc.), the result should be reported with the appropriate number of significant figures based on the data used.