Significant Figures

Question 1

Significant Digits / Figures

Answer 1

Are the reliable digits plus the first uncertain digit

Question 2

Rules to find Significant Figures (SF)

Answer 2

1) Non zero digits are significant
2) Zeros between non zero digits are significant
3) If no. less than one, then zero’s on the left side and right of decimal point are insignificant (0.002308 - 4SF)
4) Trailing zeros are insignificant except after decimal point (100 - 1SF, 100.0 - 4SF)
5) Exponential part of exponential term not counted (12.3 X 10^4 - 3SF)

Question 3

Arithmetic Operations

Answer 3

*Addition or Subtraction :-
12.587 - 12.5 = 0.087 = 0.1 (Second
term has low SF after decimal)
*Multiplication or Division :-
5.0 X 0.125 = 0.625 = 0.62 (should have SF of the term with lowest SF)

Question 4

Rounding Off

Answer 4

• Eg. - 3.85 -> 3.9
• Eg. - 3.84 -> 3.8