A certain factory produced 3 million cars in May, an increase of 500,000 compared to the plan, and what percentage was the increase compared to the plan?
某工厂五月份生产汽车300万辆，比计划增产50万辆，比计划增产百分之几？
<gadget id="calculator">300 - 50</gadget>
<output>250</output>

<gadget id="calculator">50 / 250</gadget>
<output>1/5 = around 0.2</output>

<result>1/5 = around 0.2</result>