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Wikipedia:Reference desk/Archives/Mathematics/2019 September 24

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September 24

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significant figures

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what are the significant figures in 2900 corrected to 10 . Please explain it. — Preceding unsigned comment added by 182.187.102.108 (talk) 11:20, 24 September 2019 (UTC)[reply]

Do you mean rounded to the nearest 10 ? (So 2890, 2900, 2910, etc.) ? Gives us your answer and we will comment. SinisterLefty (talk) 14:14, 24 September 2019 (UTC)[reply]
Explanation is here. DroneB (talk) 15:36, 24 September 2019 (UTC)[reply]

yes rounded to nearest 10

To expand on the article a bit, 2900 is ambiguous in terms of significant figures because it's not clear how many of the 0's, if any, are significant. You can get around this using scientific notation, i.e. 2900=2.9×103=2.90×103=2.900×103 numerically but 2.9×103 has two significant digits, 2.90×103 has three and 2.900×103 four. You can even go past the decimal with 2.9000×103 having five significant figures. If the 2900 is accurate to within 10, then the scientific notation for it would be 2.90×103 — three significant figures. --RDBury (talk) 19:00, 24 September 2019 (UTC)[reply]

I have a confusion in this, as 2895,2896,2897,2898,2899,2901,2902,2903,2904 are rounded to nearest 10, all have 4 significant figures and their is ambiguity in digits, so why answer 3 is correct — Preceding unsigned comment added by 182.187.114.240 (talk) 01:48, 25 September 2019 (UTC)[reply]

Those numbers all had 4 significant figures, but once rounded to the nearest 10, to get 2900, and then you have 3 significant figures. So why would you drop the last significant digit ? Well, if the accuracy of your measurement just isn't that good, then saying a value is 2901 is just a guess. But personally, I dislike significant digits, and would write it as 2901 ± 5, if the measurement was 2901, and the accuracy is to the nearest 5. That's a more precise way of stating things. SinisterLefty (talk) 02:06, 25 September 2019 (UTC)[reply]

2900±5 — Preceding unsigned comment added by 182.187.24.172 (talk) 02:08, 25 September 2019 (UTC) 2900 may have 2,3 or 4 significant digits[reply]