Lihuazhuang needs to dig a 600-meter-long canal. It has already dug 320 meters, and it will take another 4 days to complete the task. How many meters do you need to dig on average per day?
梨花庄要挖一条600米长的水渠，已经挖了320米，还要再挖4天才能完成任务．平均每天需要挖多少米？
<gadget id="calculator">600 - 320</gadget>
<output>280</output>

<gadget id="calculator">280 / 4</gadget>
<output>70</output>

<result>70</result>