Measuring and Recording Significant Figures

Source: National Science Olympiad Rev. 12/5/12

Significant Figures in measurement include all the digits of a number that can be read directly from the markings or graduations of the instrument or measuring device plus the digit that is estimated. The last digit (and only the last one) of a measurement should be an estimate, which is counted as a significant figure. All Science Olympiad events follow this basic measurement rule. Division B students are not expected to apply the significant figure rules below for B events (e.g., Metric Mastery) unless otherwise stated in the Event Rule. By convention, if a number is less than one, a zero should always be written to the left of the decimal point, but this zero is not significant (e.g., 0.2).

Rules on determining how many significant figures are in a number:

Rounding off rules. Examine the digit to the right of the one that is to be the last significant figure:

Calculations and significant figures:

Recommended Resources:

  1. Wikipedia Significant figures
  2. Hillsborough Community College Significant Figures Handout