When Xiao Ming goes from A to B, he travels 6,000 meters per hour, and when he returns, he travels 9,000 meters per hour. It takes 5 hours to go back and forth. How many kilometers does Xiao Ming walk back and forth?
小明从甲地到乙地去时每小时行6000米，回来时每小时行9000米，来回共用5小时，小明来回共走了多少千米？
<gadget id="calculator">6_000 / 1_000</gadget>
<output>6</output>

<gadget id="calculator">3 + 2</gadget>
<output>5</output>

<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">5 * (3/5)</gadget>
<output>3</output>

<gadget id="calculator">6 * 3 * 2</gadget>
<output>36</output>

<result>36</result>