The department store sold 35 pens in the morning, and 77 of the same pens in the afternoon, resulting in an extra income of 336 yuan in the afternoon. How much is each pen?
百货超市上午卖出钢笔35枝，下午又卖出同样的钢笔77枝，结果下午多收入336元，每枝钢笔多少元？
<gadget id="calculator">77 - 35</gadget>
<output>42</output>

<gadget id="calculator">336 / 42</gadget>
<output>8</output>

<result>8</result>