(44+25)/□=8...5, □=how much.
(44+25)/□=8…5，□=多少．
<gadget id="calculator">25 - 5</gadget>
<output>20</output>

<gadget id="calculator">44 + 20</gadget>
<output>64</output>

<gadget id="calculator">64 / 8</gadget>
<output>8</output>

<result>8</result>