So Sig Figs<3
Lets say you have 1,000,000,001 (slightly larger than 1 billion) and you wanted to express that in scientific notation as everything else you are working with is in scientific notation.
To show that you have 10 sig figs you would write 1.000000001*(10^9) which does not look pretty. Is there a better approach than writing that?
Maybe you have a number like 2.800*(10^7). The 1 billion 1 number seems to look wrong compared to something so neat as 4 sig figs of 28 million. This is before the point where you would even considering making this billion number into 4 sig figs.
maybe you would just make this into 4 sig figs and let it be and move on?
Scientific notation is what it is, there's one way to write it, namely according to the rules on how to write it. If you're not asked to write that number to that many significant figures then you don't have to, but if you are--and really you should always keep your most accurate estimates, since the rule when you use them for calculations is that you always go with the smallest number of total sig figs for the last answer.