Teacher Wang brought 100 yuan to buy school supplies, and he bought 8 pens. Get back 4 yuan, how much is each pen.
王老师带了100元钱去买学习用具，他买了8支钢笔．找回4元，每支钢笔多少元．
<gadget id="calculator">100 - 4</gadget>
<output>96</output>

<gadget id="calculator">96 / 8</gadget>
<output>12</output>

<result>12</result>