public static void parseSciNot(double num, double base, int index) {

    base = num;

    index = 0;

    if (num >= 1) {

         while (base >= 10) {

            base = base / 10;

            index ++;

        }

    }

    else {

         while (base < 1) {

        base = base * 10;

        index --;

        }

    }

    System.out.println("The scientific notation of " + num + " is: " + base + "*10^(" + index + ")");

    }

例如 3000=3*10的三次方。0.003=3*10的负三次方