Significant figures are the digits in a number that are considered to be reliable and precise. They represent the accuracy of a measurement or calculation.
Significant figures are important because they help to ensure that measurements and calculations are reported accurately and with the appropriate level of precision. They also help to maintain consistency and avoid misleading results.
The rules for determining significant figures vary slightly depending on the context, but generally, any non-zero digit is significant, and zeros at the end of a number are only significant if they are after a decimal point. For example, 1.23 has three significant figures, while 100 has only one.
Trailing zeros are only significant if they are after a decimal point. This is because zeros at the end of a number without a decimal point could be placeholders and do not necessarily add to the precision of the measurement. For example, 100 has one significant figure, but 100.0 has four significant figures.
When performing mathematical operations, the result should be reported with the same number of significant figures as the number with the least number of significant figures. For example, if you multiply 1.2 by 2.345, the result should be reported as 2.8, since 1.2 has two significant figures and 2.345 has four.