Definition Of Significant Figure And Rounding Off Examples.
Q.1. What is SIGNIFICANT FIGURE ?
SIGNIFICANT FIGURE
the significant figure in a numerical expression is defined as these digit whose value are known along with additional digit whole value is uncertain.
Eg : 24.82 cm having 3 certain digits are 2, 4, 8 and one doubtful digit is 2.Therefore, this reading has 4 significant figure.
*Rules for determining the number of significant figure :
1. Except zero(0) all the digit 1 to 9 are significant.Example : 4.25 number has 3 significant figure.
71. 435 number has 5 significant figure.
2. All digits include zero are significant if zero appears in between non-zero digit.
Example : 40.05 has 4 significant figure.
3. Zero to the left of the first non- zero digit in a number is not significant. It indicates only decimal point.
Example : 0.4 28 has 3 significant figure.
0.054 has 2 significant figure.
4. Zeros to the right of the decimal point are significant.
Example : 42.0 has 3 significant figure.
5. In exponential notation in the numerical portion gives the number of significant figure.
Example : 6.023 ×10^23 in this number has 4 significant figure.
9.58 ×10^-1 has 3 significant figure.
Q.2. What is ROUNDING OFF ?
ROUNDING OFF
the numerical expression for various measurement are generally rounded off to express the result to a required number of significant figure.
the following rules of rounding off are :-
1. If the digit following the last digit to be written is less than 5. The last digit remain unchanged.Example : 42.22 - 42.2
4.14 - 4.1.
2. If the last digit happens to be 5 then if the digit before 5 is odd then it is increases by 1.
Example : 4.335 -4.34
15.2 75 -15.28
But if the number is even then it is written as such.
Example : 14.1 45 - 14.14
6.2 25 - 6.22.
3. If the last digit is greater than 5 then the last digit is to be written is increase by 1.
Example : 2.26 - 2.3
4.38 - 4.4.
Comments
Post a Comment