Final answer:
Scientific notation clearly expresses the correct number of significant digits in a measurement, representing the precision with which the value was determined. It ensures that only measured or estimated digits are included and signals the significance of zeros where necessary.
Step-by-step explanation:
Scientific or engineering notation can effectively be used to express the correct number of significant digits in a measurement and thereby convey the precision of that measurement. When measurements are recorded, only the digits that have been actually measured or estimated can be considered significant. For instance, using a ruler that can measure down to tenths of a centimeter, a length of 36.7 cm has three significant figures; 3 and 6 are measured values, while the 7 is an estimated value. Scientific notation avoids ambiguity by clearly indicating which zeros are placeholders and which are significant. For example, the number 140 may only have two significant figures, which can be precisely shown as 1.4 × 10² in scientific notation. Conversely, if the zero is indeed significant, indicating a measurement precise to that digit (for example, 140.0), it can be written as 1.400 × 10², now with four significant figures. This notation also clarifies the precision of small numbers; a value like 0.000416 can be written as 4.16 × 10⁻⁴, which makes it apparent that there are three significant figures.