Using the three numbers 0, 3, and 7 to form a three-digit number, what is the difference between the largest number and the smallest number?
用0、3、7这三个数字组成三位数，最大数与最小数的差是多少．
<gadget id="calculator">730 - 307</gadget>
<output>423</output>

<result>423</result>