Posted by **Charles** on Wednesday, January 30, 2008 at 6:07pm.

I always thought I understood significant figures...until I attempted to tutor someone. Some of the rules seem counterintuitive. For instance...

10.070 why is it 5 sig fig's? the "0" on the right is useless. without it the # holds the same value.

20 Why is it only "1" sig fig? the "zero" is the difference between two and twenty. seems pretty sig to me.

0.01234 has "4" sig fig's. why isn't the zero to the right of the decimal sig? without it, the # doesn't hold the same value...can someone please explain the concept that I'm missing??

- math -
**drwls**, Wednesday, January 30, 2008 at 6:20pm
<<10.070 why is it 5 sig fig's? the "0" on the right is useless.>>

The fact that the zero is there beyond the decimal point means that it IS a significant figure.

<<20.: Why is it only "1" sig fig? the "zero" is the difference between two and twenty.>>

I agree. With a decimal point after the 20, it should be clear that the number is closer to 20 than 19 or 21. Therefore there are two sig figs. However, if they had just written 20 without a decimal point, then that would be one significant figure. For example: 2000 with no decimal has only one sig fig. also.

<<0.01234 has "4" sig fig's. why isn't the zero to the right of the decimal sig?>>

Until you get a nonzero number on the left side, none of the figures are significant in terms of precision; they just establish the order of magnitude. Think of writing it as 1.234*10^-2. The exponent -2. does not establish the precision, only the 1.234 does.

## Answer this Question

## Related Questions

- SIG FIGS - How many significant figures does 22.0, 0.22, 22. , 0.022? Im just ...
- Physics Sig Figs - When you are multiplying two numbers, how do you determine ...
- Chemistry - Hi, please can someone tell me if this is the right number of ...
- Chemistry - What should be the number of significant figures in the following ...
- Significant Figures - The problem is 150 - 1 - 0.182 Since the least sig. fig. ...
- Chemistry - How does Significant Figures work? If i had a number: 1,007,000 is ...
- math/chem significant figures - Which of the answers for the following ...
- Science (Chemistry!) - I just do not understand ANYTHING about multiplying/...
- Science - I'm a little confused when it comes to significant figures. Where it ...
- Significant figures in chemistry - can someone please explain significant ...