How many significant figures are there in each of the following numbers? (i) 6.005, (ii) `6.002 xx 10^(23)`, (iii) 8000, (iv) 0.0025, (v) `pi`, (vi) the sum 18.5 + 0.4235, (vii) the product `14 xx 6.345`

Explanation

(i) Four because the zeroes between the non-zero digits are significant figures.
(ii) Four because only the first term gives the significant figures and exponential term is not considered.
(iii) Four, However, if expressed in scienfitic notation as `8.0 xx 10^(3)`, it will have only one significant figure, as `8 xx 10^(3)` or `8.000 xx 10^(3)`, it will have 2,3 or 4 significant figures.
(iv) Two because the zeros on the left of the first non-zero digit are not significant.
(v) As `pi = 22/7 = 3.1428671`....., hence it has infinite number of significant figures.
(vi) Three, because the reported sum will be only upto one decimal place i.e. 18.9
(vii) Two, because the number with less least number of significance figures involved in the calculation (i.e, 14) has two significant figures.