Zeros in Sig Figs

[Chris Fults 1C]

I am a little confused on when zeros count as significant figures. I understand that in a number such as 9.00 there are three sig figs but if the number was 0.09 would 9 be the only sig fig? Also, how many sig figs would be in the number 0.0900?

[Adela Henry 1I]

0.09 would have 1 sig fig because the zeros come before the 9.
0.0900 would have 3 sig figs because there are 2 trailing zeros after the 9. the two zeros before the 9 are not counted as sig figs.

[204917020]

Leading zeroes are never significant.
Example: both 0.0009 and .9 have 1 significant figure

Trailing zeroes are only significant if they are after a decimal, or are followed by a decimal.
Example: 0.900 has 3 sig figs. 900 only has 1 sig fig. however, 900. (notice the decimal at the end) has 3 sig figs.

Captive zeroes are always significant.
Example: 905 has 3 sig figs, 80000009 has 8 sig figs.

hope this helps!

[Molly Oakes 1A]

Zeros between two significant digits and zeros to the right of the decimal point are significant. Trailing zeros in a whole number with no decimal shown are NOT significant. For example, if it just says 230, there are only two significant figures. However, if it says "230." the decimal indicates there are three sig figs.