Teacher Wang has to correct 48 essays, 6 essays per hour in the first 2 hours, and 9 essays per hour later, how many hours did Mr. Wang spend on correcting these essays?
王老师要批改48篇作文，前面2小时每小时批改6篇，后来每小时批改9篇，王老师要批改完这些作文一共花了几小时？
<gadget id="calculator">6 * 2</gadget>
<output>12</output>

<gadget id="calculator">48 - 12</gadget>
<output>36</output>

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

<gadget id="calculator">4 + 2</gadget>
<output>6</output>

<result>6</result>