From Beijing to Guangzhou, it costs 900 yuan by plane and 316 yuan by train. From Beijing to Guangzhou, how much is cheaper by train than by plane?
从北京到广州，坐飞机需要900元，坐动车需要316元．从北京到广州，坐动车比坐飞机大约便宜多少钱？
<gadget id="calculator">900 - 316</gadget>
<output>584</output>

<result>584</result>