(1070+□*289)/18=509 (fill in □, do not write the process)
(1070+□*289)/18=509(填□，不写过程)
<gadget id="calculator">1_070 / 18</gadget>
<output>535/9 = around 59.444444</output>

<gadget id="calculator">509 - (535/9)</gadget>
<output>4_046/9 = around 449.555556</output>

<gadget id="calculator">289 / 18</gadget>
<output>289/18 = around 16.055556</output>

<gadget id="calculator">(4_046/9) / (289/18)</gadget>
<output>28</output>

<result>28</result>