What is significant figure and how to calculate it

Significant figures is the total number of digits in a number . Here, are some rules for finding the value of significant figures.

Rules for determining significant figures in addition and subtraction

Here is the rule of finding the result of addition and subtraction. It should have the same number of decimal places as the term with the least number of S.F. Let’s consider one example:

Sum = 4.524 ( 3 decimal places ) + 2.3 ( 1 decimal place ) + 6.24 ( 2 decimal places )

Actual sum = 13.064 Reported sum = 13.1 ( 1 decimal place )

Rules for determining S.F. in multiplication and division

Know the basic concept of finding the results of multiplication and division . The result consists of the same number of S.F. as that of the least precise term. But not the exact numbers are included. For example :

Multiplication of 4.327 ( 4 S.F. ) X 2.8 ( 2 S.F. )

Actual product = 12.1156 Reported product = 12 ( 2 S.F. )

Rules for determining S.F. in calculations involving number of steps

How to calculate the S.F. If a calculation involves number of steps. The result contains the same number of S.F. as that of the least precise number. But not the exact numbers are included.

FAQ’s related to the rules for determining significant figures

  1. What is the importance of significant figures ?

Answer : S.F. determine the degree of uncertainty in a calculation. Several rules decide the measurement and accuracy. S.F. provides the rules for rounding off the number.

2. Does 0 count as significant figures ?

Answer : The 0 is significant when present to the right of the decimal point. it is also important when comes between 2 other S.F.

Basic concepts for calculating significant figures @basicsofchemistry.com
  1. All non zero digits and

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