A certain automobile factory produced 3,640 cars in January, 390 more than the original plan, by what percentage?
某汽车制造厂一月份生产小汽车3640辆，比原计划多生产390辆，超产百分之几？
<gadget id="calculator">3_640 - 390</gadget>
<output>3_250</output>

<gadget id="calculator">390 / 3_250</gadget>
<output>3/25 = around 0.12</output>

<result>3/25 = around 0.12</result>