Significant figure is generally used to find accuracy of number. Basically it is used in measuring accurate figures of measurement. It is introduced to the students in Introductory Science. It is similar to rounding of figures but it is different because of certain specified rules. It generally describes the uncertainty in the value. It describes the concept of precision and accuracy.
We can perform all mathematical operations on Significant Figures like: Multiplying significant figures, adding significant figures, subtracting or dividing significant figures. Some basic rules which should be kept in mind while performing operations are:
If a decimal Point is present in a number, leading zeros”0” are not significant and all digits except leading zero are significant (including zero terms enclosed in non zero Numbers).
If a number given to us is a Whole Number, again trailing zeros are not significant. All other digits including Zero terms are significant.
Zero term which is present between two non zero terms in a given number is counted as significant term.
Numbers with zero at the end of terms may count as significant in some cases of decimal place.
Some basic examples of Significant figures are: When a thermometer reads temperature as 33.56oC we have 4 significant figures in it, a stop watch which stores 22.345 seconds has 5 significant figures and the bus travels 01.2 miles in 3 hours has 2 significant figures.
While multiplying two significant figures the resultant should have the significant figure same as the number with least significant figure. This can be explained by the example given below:
12.45 * 0.023
12.45 ----> four significant figures 1, 2, 4, 5
0.023 ----> two significant figures 2, 3
The least significant figure is 2, so the result should have 2 significant figure.
12.45 * 0.023 = 0.28635
12.45 * 0.023 = 0.29