Xiaoqiang has to do 315 cross-point math problems. He has done it for 4 days, and there are 115 problems left to do. How many cross-point math problems does Xiaoqiang do on average every day?
小强要做315道口算题，已经做了4天，还剩115道没有做，小强平均每天做多少道口算题？
<gadget id="calculator">315 - 115</gadget>
<output>200</output>

<gadget id="calculator">200 / 4</gadget>
<output>50</output>

<result>50</result>