Xiao Ming rides a bicycle from place A to place B. The distance between the two places is 12 kilometers. When he goes there, he travels 6 kilometers per hour, and when he returns, he travels 4 kilometers per hour. How many kilometers per hour does Xiao Ming travel back and forth on average?
小明骑车从甲地到乙地，两地相距是12千米，他去时每小时行6千米，回来时每小时行4千米，小明来回平均每小时行多少千米？
<gadget id="calculator">12 * 2</gadget>
<output>24</output>

<gadget id="calculator">12 / 6</gadget>
<output>2</output>

<gadget id="calculator">12 / 4</gadget>
<output>3</output>

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

<gadget id="calculator">24 / 5</gadget>
<output>24/5 = around 4.8</output>

<result>24/5 = around 4.8</result>