Question:
Suppose you are asked to find the area of a rectangle that is 2.1-cm wide by 5.6-cm long. Your calculator answer would be 11.76cm2. Now suppose you are asked to give the answer to two significant figures. What is the answer?
Significant Digits:
The significant digits or figures of a number indicate the quantity of digits that are necessary to represent the number, or that are within the resolution of the device used for the measurement.
For example:
0.012 has 2 significant figures;
1.012 has 4 significant figures
For a ruler with 1mm resolution, 12.1250cm has 3 significant figures