It took 5 days to build a section of 810-meter road, but there are still 450 meters left to be repaired. How many meters are repaired per day on average?
修一段810米的公路，修了5天，还有450米没有修，平均每天修多少米？
<gadget id="calculator">810 - 450</gadget>
<output>360</output>

<gadget id="calculator">360 / 5</gadget>
<output>72</output>

<result>72</result>