The Limits of Significant Figures
Significant figures are a basic means that scientists use to provide a measure of precision to the numbers they are using. The rounding process involved still introduces a measure of error into the numbers, however, and in very high-level computations there are other statistical methods that get used. For virtually all of the physics that will be done in the high school and college level classrooms, however, correct use of significant figures will be sufficient to maintain the required level of precision.Final Comments
Significant figures can be a significant stumbling block when first introduced to students, because it alters some of the basic mathematical rules that they have been taught for years. With significant figures, 4 x 12 = 50, for example.Similarly, the introduction of scientific notation to students who may not be fully comfortable with exponents or exponential rules can also create problems. Keep in mind that these are tools which everyone who studies science had to learn at some point, and the rules are actually very basic. The trouble is almost entirely remembering which rule is applied at which time. When do I add exponents and when do I subtract them? When do I move the decimal point to the left and when to the right? If you keep practicing these tasks, you'll get better at them until they become second nature.
Finally, maintaining the proper units can be tricky. Remember that you can't directly add centimeters and meters, for example, but must first convert them into the same scale. This is a very common mistake for beginners but, like the rest, it is something that can very easily be overcome by slowing down, being careful, and thinking about what you're doing.
