Xiao Ming’s distance from home to school is 540 meters, and it takes Xiao Ming 9 minutes to go to school, and it takes two minutes less to go home than to go to school. So how many meters does Xiao Ming walk on average per minute for the round trip?
小明从家到学校的路程是540米，小明上学要走9分钟，回家时比上学少用两分钟，那么小明往返一趟平均每分钟走多少米？
<gadget id="calculator">540 * 2</gadget>
<output>1_080</output>

<gadget id="calculator">9 - 2</gadget>
<output>7</output>

<gadget id="calculator">9 + 7</gadget>
<output>16</output>

<gadget id="calculator">1_080 / 16</gadget>
<output>135/2 = around 67.5</output>

<result>135/2 = around 67.5</result>