# Help with significant digits

1. Sep 25, 2009

### parabolic1

just a quick question.... (not a HW question)

i know that when you do multiplication/division between numbers you take the lowest amount of sig figs of the two and apply it to your answer... HOWEVER:

what would be the answer for a question such as:

0.00420 x 60 = ?

the first part has 3 sig figs, while the second part has 1... although i've heard you don't count whole integers, so would the answer be

0.252 or 0.3 ?

thanks

2. Sep 25, 2009

### mathman

The "60" is ambiguous. For example if you are converting from minutes to seconds, 60 is exact, so it has to be treated as having infinite significant digits. To answer your question you need more context.

3. Sep 26, 2009

### Andy Resnick

Since there's no decimal point with the '60', it has 1 significant digit.

4. Sep 26, 2009

### Redbelly98

Staff Emeritus
On the other hand, if the 60 is meant to be a conversion factor (i.e, between minutes and seconds, or hours and minutes), then it is to be treated as an exact number that doesn't limit the significant figures.

But yes, if it's just part of the data then 1 significant figure, definitely.