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

Double number = new Double("5.25");
Double tDouble = 
  new BigDecimal(number).setScale(1, BigDecimal.ROUND_HALF_UP).doubleValue();

this will return it will return 5.3

Answer 2

Helpful method I created a while ago...

private static double round (double value, int precision) {
    int scale = (int) Math.pow(10, precision);
    return (double) Math.round(value * scale) / scale;
}

Answer 3

Your method is right, all you have to do is add a .0 after both the tens and it will fix your problem!

double example = Math.round((187/35) * 10.0) / 10.0;

The output would be:

5.3