Aunt Zhang from the landscaping office trimmed 36 apple trees from 8:00 am to 12:00 am. How many trees does she prune on average per hour?
园林绿化所的张阿姨早晨8时到12时，共给36棵苹果树做了修剪，她平均每小时修剪多少棵树？
<gadget id="calculator">12 - 8</gadget>
<output>4</output>

<gadget id="calculator">36 / 4</gadget>
<output>9</output>

<result>9</result>