How many sig figs when in decimals?

[Bryce Ramirez 1J]

How many sig figs are there for 0.0001? Because 1 is the last number and includes all the zeros, I thought it would be four, but it says that the amount is 1? What is the rule for zeros in this case?

[SVajragiri_1C]

In a decimal, you start counting sig figs at the first non-zero digit, whether it be before or after the decimal point.
So for example,
0.00345 has 3 sig figs.
3.034 has 4 sig figs.
0.0200 has 3 sig figs.

[Tooba_1A]

There would only be one sig figs, considering that the only significant number (1), only appears after 4 other zeroes, all of which aren't considered significant. Some factors that could have changed this outcome is there being another number before the zeroes, deeming all the zeroes after a significant and making it 5 significant figures. Additionally, if there had been zeroes after the 4, those would have been counted as well since they had occurred after an important number.

[Tooba_1A]

There would only be one sig figs, considering that the only significant number (1), only appears after 4 other zeroes, all of which aren't considered significant. Some factors that could have changed this outcome is there being another number before the zeroes, deeming all the zeroes after a significant and making it 5 significant figures. Additionally, if there had been zeroes after the 4, those would have been counted as well since they had occurred after an important number.

[Pipiena Malafu 3J]

Long story short, leading zeroes (or zeroes before numbers other than zero) are never significant and thus there is only one significant figure for numbers like "0.002" and such.

[J Medina 2I]

I was reading through the link "EVERYTHING YOU WANTED TO KNOW ABOUT SF" posted on the class website to review significant figures and was confused when I read that if a number ends in the number '5' and you are rounding, that you must round the number up or down to the nearest even number. I always thought a number ending in '5' always meant to round up. In the example given 2.65 turns into 2.6 when rounded. Is anyone else unfamiliar with this rule?

[205154661_Dis2J]

I attended Step-Up session today and we went over sig figs. The UA told us to remember this:
1) Non-zero digits are always significant.
2) Any zero between two digits are significant.
3) Final zero or trailing zero in decimal portion ONLY are significant.
Hope this helps!