Decimals After Whole Numbers

[Kguox1B]

In class, we saw an example where the number "100." had 3 significant figures. Does the fact that there is a decimal point after change the sig fig in any way?

[Chem_Mod]

Yes. 100 only has 1 sig fig while 100. has 3 sig figs. The decimal part is an important factor if you are dealing with 0's.

Important too, .001 has 1 sig fig, while .100 has 3 sig figs for example. .00100 would have 3.

[Jocelyn Thorp 1A]

Yes. 100 only has 1 sig fig while 100. has 3 sig figs. The decimal part is an important factor if you are dealing with 0's.

Important too, .001 has 1 sig fig, while .100 has 3 sig figs for example. .00100 would have 3.

Thanks for the inclusion of the zeroes after the decimal but before any nonzero values. I always get confused when it's something like .000023;

I suppose the simplest way to remember (for me at least) would be if they would be significant if you were writing in scientific notation (ex: you wouldn't include the zeroes in .000023 as 2.3*10^-5 but you would for .3400 as 3.400*10^-1).

[DMuth_1J]

A good way to remember this that I always use is that, when writing normal numbers, you could also write 002, which is still two. But we intuitively ignore the zeros before the important digit. It applies similarly to decimals. For example, (.002) is still one significant figure.

[Sara Richmond 2K]

Do any of you have a video recommendation to review significant figures? It has been a long time since I've looked at significant figures?

[britthanul234]

Where the decimal point is placed is super important when it comes to significant figures. 100 would be 1 sig fig because you don't count the zeroes after the 1. However, 100. would be 3 sig figs because you must count all digits that come before the period as long as the digits coming before the decimal point are not all zeroes.

[Sarah Zhari 1D]

Here's quite a good video on sig figs: https://www.youtube.com/watch?v=hQpQ0hxVNTg (it starts from about 5:40)
The explanations are quite thorough.