This method will transform a string to a number by removing non numbers characters (for memo)

removeNonNumerics

public static String removeNonNumerics(String text) {

    //remove everything except + - and digits
    String num = text.replaceAll("[^-+\\.\\d]", "");

    if (num.length() > 0) {
      //remove + and - in middle of the string
      num = num.charAt(0) + num.substring(1).replaceAll("[-+]", "");

      //remove extra . (keep the first)
      final int dot = num.indexOf(".");
      if(dot > -1 && dot < num.length()){
        //Note: in case dot == num.length() - 1, this returns ""
        final String afterdot = num.substring(dot+1);
        final String beforedot = num.substring(0, dot + 1);
        num = beforedot + afterdot.replaceAll("\\.","");
      }

    }
    return num;
  }