Math.round()

Hi

I have a problem facing might seems very small but just couldnt do it.
I want to roundup a value up to one decimal only. For example,
x=100.238294;
trace(Math.round(x*10)/10)
this works fine but if the number is : 100.0000000000

then I want my output to be 100.0. But its showing 100 only. Does anyone knows how to get this done or any other way to do it. Please let me know .Thanx

Ashish