The ballpoint pens in stationery stores are 3.5 yuan each, and the price of fountain pens is 4 yuan more than six times that of ballpoint pens. How much is each pen?
文化用品商店的圆珠笔每支3.5元，钢笔的价钱比圆珠笔的六倍还多4元．每支钢笔多少元？
<gadget id="calculator">3.5 * 6</gadget>
<output>21</output>

<gadget id="calculator">21 + 4</gadget>
<output>25</output>

<result>25</result>