Xiao Ming’s distance from home to school is 540 meters. It takes him 6 minutes to go to school, and it takes 2 minutes less to get home than to go to school. So how many meters does Xiao Ming walk per minute on average for the round trip?
小明从家到学校的路程是540米，他上学要走6分钟，回家时比上学少用了2分钟，那么小明往返一趟平均每分钟要走多少米？
<gadget id="calculator">6 - 2</gadget>
<output>4</output>

<gadget id="calculator">6 + 4</gadget>
<output>10</output>

<gadget id="calculator">2 / 10</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">540 * (1/5)</gadget>
<output>108</output>

<result>108</result>