The Experimental Primary School built a 400-meter-long circular plastic runway, and 130 meters have been completed. The rest will be completed within 30 days. How many meters will be built on average every day?
实验小学修筑一条长400米的环形塑胶跑道，已经完成了130米，剩下的要在30天内完成，平均每天要修筑多少米？
<gadget id="calculator">400 - 130</gadget>
<output>270</output>

<gadget id="calculator">270 / 30</gadget>
<output>9</output>

<result>9</result>