Basic question, other answers I found didn't really seem to address this.
N[x,3] seems to only work if x is analytic instead of numeric. But it seems it would be very simple for the function to also take a decimal and give you 3 significant digits, yet it doesn't. Can anyone give a good reason why N is not designed to do this? I'm aware SetPrecision[x,3] can do the job, but why not N?
In[277]:= N[1/3, 3]
Out[277]= 0.333
In[279]:= N[0.33333, 3]
Out[279]= 0.33333