□*1.5-3.6=2.4, what number should be filled in □.
□*1.5-3.6=2.4，□中应填的数是多少．
<gadget id="calculator">2.4 + 3.6</gadget>
<output>6</output>

<gadget id="calculator">6 / 1.5</gadget>
<output>4</output>

<result>4</result>