Uncle Zhang rides a bicycle to work and travels 4 kilometers in 0.5 hours. How many kilometers does he travel per hour?
张叔叔骑自行车上班，0.5小时行了4千米，每小时行多少千米？
<gadget id="calculator">4 / 0.5</gadget>
<output>8</output>

<result>8</result>