Final answer:
Significant figures are important because they help us correctly represent the certainty of values and avoid overestimating precision. They also help express uncertainties associated with measurements and computations.
Step-by-step explanation:
The importance of significant figures lies in their application to fundamental computation. In addition and subtraction, the sum or difference should contain as many digits the right of the decimal as that in the least certain of the numbers used in the computation. This is done to correctly represent the certainty of the values reported and to ensure that a calculated result is not represented as being more certain than the least certain value used in the calculation.
For example, if you are adding 3.45 and 0.6, since 0.6 has only one digit to the right of the decimal, the sum should have only one digit to the right of the decimal as well, so the correct answer is 4.0.
Significant figures help us avoid overestimating the precision of our calculations and provide a way to express the uncertainties associated with measurements and computations.