Subtraction of double type data in Java

Subtraction public class Arith {for double type data in Java
private static final int def_div_scale = 10;

/**
* Two double number added
* @param v1
* @param v2
* @return Double
*/
public static double Add (Double v1,double v2) {
BigDecimal B1 = new BigDecimal (v1.tostring ());
BigDecimal b2 = new BigDecimal (v2.tostring ());
Return B1.add (B2). Doublevalue ();
}

/**
* Subtract two double numbers
* @param v1
* @param v2
* @return Double
*/
public static double sub (double v1,double v2) {
BigDecimal B1 = new BigDecimal (v1.tostring ());
BigDecimal b2 = new BigDecimal (v2.tostring ());
Return B1.subtract (B2). Doublevalue ();
}

/**
* Two double number multiplied
* @param v1
* @param v2
* @return Double
*/
public static double Mul (Double v1,double v2) {
BigDecimal B1 = new BigDecimal (v1.tostring ());
BigDecimal b2 = new BigDecimal (v2.tostring ());
Return b1.multiply (B2). Doublevalue ();
}

/**
* Divide two double numbers
* @param v1
* @param v2
* @return Double
*/
public static double div (Double v1,double v2) {
BigDecimal B1 = new BigDecimal (v1.tostring ());
BigDecimal b2 = new BigDecimal (v2.tostring ());
Return B1.divide (B2,DEF_DIV_SCALE,BIGDECIMAL.ROUND_HALF_UP). Doublevalue ();
}

/**
* Divides two double numbers and preserves scale decimal places
* @param v1
* @param v2
* @param scale
* @return Double
*/
public static double div (double v1,double v2, int scale) {
if (Scale < 0) {
throw New IllegalArgumentException (
"The scale must be a positive integer or zero");
}
BigDecimal B1 = new BigDecimal (v1.tostring ());
BigDecimal b2 = new BigDecimal (v2.tostring ());
Return B1.divide (B2,SCALE,BIGDECIMAL.ROUND_HALF_UP). Doublevalue ();
}

}