Question

How many significant figures are there in each of the following numbers?
a. `pi`
b. The sum of `16.4 + 0.3254`
c. The product of `12 xx 7.435`
d. 0.0075
e. `5.033 xx 10^(22)`
f. 7.007
g. 6000
h. The subtractin of 19.3 - 0.4567

Answer 1

a. As `pi = (22)/(7) = 3.1428571`…, hence it has infinite number of significant figures.
b. The result should have upto one decimal point in 16.4. The sum is 16.7254. So, the result is 16.7. So, it has three significant figure.
c. Two significant figures. The product is 89.22. The result is reported with least number of significant figures involved in the calculation
d. Two significant figures because the zeros on the left of the first non-zero number are not significant.
e. Four significant figures becuase the first term gives the significant figures and exponential term is not considered.
f. Four significant figures because the zeros between the non-zero digits are significant figures.
Four significant figures. But in scientific of exponential notation significant figure vary, e.g., `6.0 xx 10^(3)` has two significant figures, `6.00 xx 10^(3)` or `6.000 xx 10^(3)` has three of four significant numbers, respectively.
Three significant figures becuase the number with least significant figures involved in the calculation has three siginficant figures.