From point A to point B, Xiao Ming first rides a bicycle for half of the distance, 12 kilometers per hour, and walks the rest at 4 kilometers per hour. How many kilometers per hour is the average speed of Xiaoming traveling the entire distance?
小明从A地到B地，先骑自行车行完全程的一半，每小时行12千米，剩下的步行，每小时走4千米．小明行完全程的平均速度是每小时行多少千米．
<gadget id="calculator">12 / 12</gadget>
<output>1</output>

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

<gadget id="calculator">1 + 3</gadget>
<output>4</output>

<gadget id="calculator">24 / 4</gadget>
<output>6</output>

<result>6</result>