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I want to write 45,000 with some numbers of significant figures.

It's really easy to write it with 2 significant figures: 45,000

5 significant figures is also easy: 45,000.

6 and up is also easy: 45,000.0

But how do I write it with 3 or 4 significant figures? I know it can be done with scientific notation, but I want to see if there's a way without it, since scientific notation can sometimes make the size of a number less visually obvious. Is this just a lexical gap with the notation, or is there a way to do it?

SarcasticSully
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3 Answers3

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use scientific notation:

2 significant digits can be represented by: $4.5 $x$(10^4)$

3 significant figures can be represented by: $4.50 $x$(10^4)$

4 significant figures can be represented by: $4.500 $x$(10^4)$

Sina Babaei Zadeh
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    Is scientific notation the only way to note that? – SarcasticSully Aug 29 '19 at 03:39
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    That was what I was taught in school. I have never seen another way to do it. Multiple sources also do it this way:https://en.wikipedia.org/wiki/Significant_figures https://www.rpi.edu/dept/phys/Dept2/APPhys1/sigfigs/sigfig/node12.html – Sina Babaei Zadeh Aug 29 '19 at 03:42
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I was taught that you could show that with an underline, so $45,0\underline00$ would have four significant figures. I have never seen it since, so I wouldn't expect people to understand it.

Ross Millikan
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  • I’ve seen that too. For example, here: https://www.me.psu.edu/cimbala/Learning/General/Dimensions_units_significant_digits.pdf – Joe Aug 29 '19 at 03:22
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If the number has a unit U, you can abbreviate the unit and add decimals as appropriate:

2 significant figures: $45$ kU

3 significant figures: $45.0$ kU

4 significant figures: $45.00$ kU

Williham Totland
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