It has been 3 days to build a road with a length of 1500 meters, and there are 600 meters left. How many meters are repaired per day on average?
修一条长1500米的路，已经修了3天，还剩600米，平均每天修多少米？
<gadget id="calculator">1_500 - 600</gadget>
<output>900</output>

<gadget id="calculator">900 / 3</gadget>
<output>300</output>

<result>300</result>