Rounding to 2 decimals with the math method

So I'm working on an assignment where I'm supposed to do a table with different values etc. But I have run into a problem where the (charging time/laddningstid(h)) round up to 16.0 when I want it so say 15.57. Since 35.8/2.3 = 15.57.

So my question is what have I done wrong here? How can I make it say the correct value instead of 16.0

CODE:

class Main {
  public static void main(String[] args) {

    double batteryEffect = 35.8;
    int current = 10;
    int current1 = 16;
    int current2 = 32;

    int voltage = 230;
    int voltage1 = 400;

    
    double calcEffect = 0;

    int noOfDecimals = 2;
    double scale = 0;
    scale = Math.pow(10, noOfDecimals);
    calcEffect = Math.round(current*voltage)*scale/scale/1000;

    
    double calcCharge = 0;

    calcCharge = Math.round(batteryEffect/calcEffect)*scale/scale;
    

    System.out.print("Batteri" + " " + batteryEffect + "(kWh)");
    System.out.print("\n");
    System.out.print("\nStröm(A)\tSpänning(V)\tLaddeffekt(kW)\tLaddningstid(h)");  
    System.out.print("\n=======================================================");
    System.out.print("\n");
    System.out.print(current + "\t\t\t" + voltage + "\t\t\t"  + calcEffect + "\t\t\t\t" + calcCharge);
    System.out.print("\n");
    System.out.print(current1 + "\t\t\t" + voltage);
  }
}

EDIT: My bad I didn't know the picture was gonna get that small first time posting here.