A truck plans to transport 52 tons of goods, has been transported 7 times, and the remaining 20.5 tons have not been transported. How many tons are shipped on average?
一辆卡车计划运52吨货，已经运了7次，还剩20.5吨没有运．平均每次运多少吨？
<gadget id="calculator">52 - 20.5</gadget>
<output>31.5</output>

<gadget id="calculator">31.5 / 7</gadget>
<output>4.5</output>

<result>4.5</result>