When Doudou was doing a multiplication problem, he mistakenly wrote a multiplier of 36 as 30, and the result was 540. What is the correct answer?
豆豆在做一道乘法题时，误将一个乘数36写成了30，结果得540，正确的答案是多少．
<gadget id="calculator">540 / 30</gadget>
<output>18</output>

<gadget id="calculator">18 * 36</gadget>
<output>648</output>

<result>648</result>