public double convert(String input){
        boolean isNeg = false;
        if(input.startsWith("-")){
            isNeg = true;
            input = input.substring(1);
        }
        StringTokenizer strtk = new StringTokenizer(input,"E");
        String number = strtk.nextToken();
        String power = strtk.nextToken();
        double dNumber = toDouble(number);
        double dPower = toDouble(power);
        double pow = Math.pow(10, dPower);
        double result = dNumber * pow;
        return isNeg ? result * -1 : result;
    }
http://www.careercup.com/question?id=4901629824335872
e.g
-99.01E-2 -> -.9901
845.67E2  -> 84567.0
src/com/interview/misc/FloatPointConversion.java