Sig Figs and Zeroes

[Rachel Kho Disc 2G]

I always have trouble with determining significant figures when zeroes are involved, either before or after the decimal place. Does anyone have any concise or definite rules about how to deal with zeroes in sig figs?

[Eva Becker]

Zeros are counted in sig figs when they occur after a decimal, assuming there is an integer that comes first. 0.0050 has 2 sig figs because even though there are 2 zeros that came after a decimal, the only zero that should be counted is the zero that came after the integer (5) following the decimal. Additionally, zeros are only counted as sig figs following a whole number if there is a decimal at the end of the integer. 5000. has 4 sig figs because the 3 zeros after the 5 are followed by a decimal. If, however, there was no decimal, 5000 would only have 1 sig fig.

[miguel zatarain 2B]

This might be confusing but if there is a number such as 0.5 or 0.0005 then the number of significant figures is 1 and if it were 5.005 then the number of significant figures is 4. Lastly, if there is a number such as 0.500 then the number of sig figs is 3 (only the .500)

[Agustina Santa Cruz 2F]

Hi! Basically the rules for significant figures are:
1) non-zero numbers are always significant
2) any zeros between non-zero numbers are significant
3) a final zero in the decimal portion of a number is significant (ex. 111.900) 6 sigfigs
* zeros after a decimal but before a non-zero don't count though, aka leading zeros (ex. .005) 1 sigfig
* trailing zeros before a decimal are only significant if the decimal is shown (ex. "4000" has one sigfig vs. "4000." has four sigfigs)

[rita_debbaneh2G]

When it comes to zeroes and the decimal place, just remember this. If there IS a decimal place, trailing zeroes are sig figs. This is regardless of if they are before or after the decimal place. If there is NO decimal place, trailing zeroes are not sig figs. So at the end of the day, it depends on the presence of the decimal :)

[TiffanyBrownfield 2I]

Basically, the only zeroes that matter are the ones contributing to the actual precision of the measurement. For example, to put it into practice, if you were to have 5 grams of a substance, you can see that there is only one sig fig. If you were to convert that to kilograms you would have .005 kg. Still, this number only has one sig fig because the leading zeroes aren't adding to the precision of the measurement. With trailing zeroes, the zeroes are only considered significant if a decimal point is specified. The number 2000 would only have 1 sig fig because we aren't sure if the number was rounded for conveniency or if the tool of measurement wasn't precise enough to get an accurate measurement. However if it was written as 2000.0, you would have 5 sig figs because the decimal is clarifying that the sample was measured precisely to the tenths place, and therefore the zeros are contributing to the precision of the measurement. Sorry if that doesn't make that much sense.