Significant Figures
That depends on your goals AND on your measuring capabilities.
The answer depends on whether you are measuring the drops from a slow drip or the number of drops of water in an ocean!
3 significant figures.
5 significant figures.
Estimated
estimated
The degree of accuracy of the measuring instrument.
The least count of a measuring instrument is the smallest value that can be measured with the instrument. It determines the precision of the measurement. Significant figures, on the other hand, are the digits in a number that carry meaning about the precision of the measurement. The number of significant figures in a measurement is related to the least count of the instrument used to make that measurement.
The measurement of the keyword "length" typically has an infinite number of significant figures, as it can vary in precision depending on the context and measuring instrument used.
The significant figures in a measurement of length and width depend on the precision of the measuring instrument used. Unless specified otherwise, we typically use the number of markings on the measuring instrument to determine the significant figures.
Significant Figures
They tell you what level of precision you can expect from measurements that are made using that instrument.
Significant figures are basically the amount of digits in a number. E.g. 2.576 has 4 significant figures 32.545 has 5 significant figures Zeroes before the first non-zero digit and after the last non-zero digit are not counted as significant figures. E.g. 0067.4 has 3 significant figures 67.400 has 3 significant figures 0067.400 has 3 significant figures. In case of thermometer measurement of normal temperatures maximum three digits are significant because most of the thermometers indicate one digit after decimal; as 37.4.
That depends on your goals AND on your measuring capabilities.
The number of significant figures in a measurement is determined by the precision of the measuring instrument. Include all certain digits plus one uncertain digit (estimated or interpolated). Nonzero digits, zeros between nonzero digits, and trailing zeros in numbers containing a decimal point are considered significant.
No, the units are independent of the accuracy. If you are measuring volume, how accurate the measurement is (or isn't) will not affect what you are measuring - it will always be volume.