Understanding Significant Figures
An important part of any curriculum in the sciences, mathematics, or engineering is the concept of significant figures. Enroll in a degree program in any of these areas and the first thing you will learn in your first semester—I’m not exaggerating here, it’s literally the first topic covered in multiple introductory classes—is how to use significant figures. What are they? And why are they important? Let’s find out. Estimation and Uncertainty When we measure things, our results are subject to uncertainty. The degree of uncertainty is determined by the method and accuracy of the measurement, but there is always uncertainty . If I use a ruler marked off in millimeters (like the tape measure above) to measure something and it looks like it is 25 mm long, it might actually be 25.0001 mm or 24.999999 mm—but my ruler, which doesn’t have that degree of accuracy, won’t show that. So how do we arrive at a length for this object? Well, we estimate the last number beyond the...