The price of 3 fountain pens is equal to the price of 6 ballpoint pens. 8 yuan per pen, how much is each ballpoint pen?
3支钢笔的价钱与6支圆珠笔的价钱相等．每支钢笔8元，每支圆珠笔多少元？
<gadget id="calculator">6 / 3</gadget>
<output>2</output>

<gadget id="calculator">8 / 2</gadget>
<output>4</output>

<result>4</result>