How to calculate significant figures of a number? I got confuse as the number 28600 has 3 significant figure instead of 5. Anyone can explain?
The number of significant digits in 28600 depends on what the error in the measurement is. If sigma = 15 Then we can write 28600(15) and there are 5 significant digits. If sigma = 1800 then we can write 28600 +-1800 and there are 3 significant digits. If sigma = 25000 then we can write 2.9(25)x10^4 and there are 2 significant digits. Significant digits are the work of the devil and cause much confusion. Calculate the uncertainty first and then you can calculate how many significant digits there are.