A rectangular vegetable field is 20 meters long and 8 meters wide. It takes Xiaolin 7 minutes to walk around the side of the vegetable field. How many meters does he walk per minute on average?
一块长方形菜地，长20米，宽8米，小林沿着菜地的边走一圈要用7分钟，他平均每分钟走多少米？
<gadget id="calculator">20 + 8</gadget>
<output>28</output>

<gadget id="calculator">28 / 7</gadget>
<output>4</output>

<gadget id="calculator">2 * 4</gadget>
<output>8</output>

<result>8</result>