Known: □*18+18*18=1800, how much to fill in □.
已知：□*18+18*18=1800，□内填多少．
<gadget id="calculator">18 * 18</gadget>
<output>324</output>

<gadget id="calculator">1_800 - 324</gadget>
<output>1_476</output>

<gadget id="calculator">1_476 / 18</gadget>
<output>82</output>

<result>82</result>