Using Math.round to round to one decimal place?

Question

I have these two variables

double num = 540.512
double sum = 1978.8

Then I did this expression

double total = Math.round((         


        

Answer 1

A neat alternative that is much more readable in my opinion, however, arguably a tad less efficient due to the conversions between double and String:

double num = 540.512;
double sum = 1978.8;

// NOTE: This does take care of rounding
String str = String.format("%.1f", (num/sum) * 100.0); 

If you want the answer as a double, you could of course convert it back:

double ans = Double.parseDouble(str);