Little sloppy is doing a multiplication problem. He regards one of the multipliers, 21, as 12. The resulting product is 216 less than the correct product. So what is the correct product?
小马虎做一道乘法题，他把其中一个乘数21看成了12，结果得到的积比正确的积少216，那么正确的积是多少．
<gadget id="calculator">7 / 4</gadget>
<output>7/4 = around 1.75</output>

<gadget id="calculator">(7/4) - 1</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">216 / (3/4)</gadget>
<output>288</output>

<gadget id="calculator">288 * (7/4)</gadget>
<output>504</output>

<result>504</result>