Do sig figs only refer to decimals?

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Brianna Brockman 1F
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Joined: Fri Sep 28, 2018 12:23 am

Do sig figs only refer to decimals?

Postby Brianna Brockman 1F » Wed Oct 03, 2018 4:31 pm

So I'm a little confused... Do sig figs refer only to the number of figures after a decimal point (say 1.02), or do they refer to the whole number, before and after the decimal? So would, say, the number 1.02 have 2 sig figs, or 3?

Rachana Jayaraman 1H
Posts: 61
Joined: Fri Sep 28, 2018 12:26 am

Re: Do sig figs only refer to decimal?

Postby Rachana Jayaraman 1H » Wed Oct 03, 2018 4:38 pm

Sig figs refer to the entire number. The rules are:
1. leading zeros are never significant (ex: 0.00456 = 3 sig figs)
2. trailing zeros are significant if decimal point is specified (ex: 120. = 3 sig figs)
3. Imbedded zeros are always significant (ex: 1034 = 4 sig figs)

So in the case of 1.02, it is 3 sig figs.

Elena Maneffa 1E
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Joined: Fri Sep 28, 2018 12:27 am
Been upvoted: 1 time

Re: Do sig figs only refer to decimals?

Postby Elena Maneffa 1E » Wed Oct 03, 2018 4:40 pm

From my understanding, I think sig figs represent all the digits, not just the figures after the decimal point. 1.02, for example has 3 sig figs.

Shash Khemka 1K
Posts: 38
Joined: Fri Sep 28, 2018 12:18 am

Re: Do sig figs only refer to decimals?

Postby Shash Khemka 1K » Wed Oct 03, 2018 4:45 pm

Hey, Brianna, sig figs do not only refer to decimals, but they can also actually refer to any integer at all.
Keep these 3 rules in mind:
1) All nonzero numbers are significant
Ex) 1,2,3,4,5, ...

2) When a zero is surrounded by nonzero numbers, it is considered significant. This can also apply to more than one zero as long as it is surrounded by nonzero numbers.
It's kinda like a zero sandwich in a sense.
Ex) 101 has 3 sig figs and 100001 has 6 sig figs

3) When a decimal is in a number, the first nonzero number (and everything after it) will be significant.
Ex) 0.6 has 1 sig fig and 0.6000 has 4 sig figs and 1.23 has 3 sig figs

For your question, the number 1.02 would have 3 sig figs due to rules 2 and 3.

Oh, also, if you find yourself still needing help understanding Sig Figs, Dr. Lavelle has a link on his 14A website labeled "Everything you want to know about Sig Fig".

Hope this helped you!


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