Significant Digits Help?

Question

Did I do this right? If I'm wrong, can you tell me why, and what the correct answer is. Thanks!

1) 110= 2 Significant Digits

2)600.0= 2 Significant Digits

3) 7040= 3 Significant Digits

Answer 1

according to this website http://www.chem.tamu.edu/class/fyp/mathr... (about half way down)

I think the 2nd one is 4 and the rest are right.  Doesn't make sense to me, but I assume the site is correct.

Answer 2

1) Yes

2) No - Since you've put a decimal this problem is now saying I know this object weighs exactly 600.0 lbs (for example) so all of the digits are significant...4 sig figs

Note as a comparison 600. would have 3 whereas 600 would only have 1 sig fig.  The reason is because the number 600 could be rounded from 643 (if I round to the hundreds place), but the addition of the decimal there tells the reader I measured it to this specific precision.

3) yes!

Try the site and see if it helps...it doesn't have every rule, but it has quite a bit on zero...zero is tricky with sig figs.. good luck.

Answer 3

1 is right because the zero after has no meaning. question 2 should be 4 significant digits because zeros after a decimal count as a sig-dig and so you will have to take into consideration the zeros in between too. and the last one is right as well.