# How do I denote only some zeros as significant

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?

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$$(10^4)$$

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.

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