The formula □/10=18…△, fill in the maximum number of the dividend.
算式□/10=18…△，被除数最大填多少．
<gadget id="calculator">10 * 18</gadget>
<output>180</output>

<gadget id="calculator">10 - 1</gadget>
<output>9</output>

<gadget id="calculator">180 + 9</gadget>
<output>189</output>

<result>189</result>