A fountain pen is 24 yuan, which is 6 times the price of a ballpoint pen. How much is a fountain pen more expensive than a ballpoint pen?
一支钢笔24元，是一支圆珠笔价钱的6倍，一支钢笔比一支圆珠笔贵多少元？
<gadget id="calculator">24 / 6</gadget>
<output>4</output>

<gadget id="calculator">6 - 1</gadget>
<output>5</output>

<gadget id="calculator">4 * 5</gadget>
<output>20</output>

<result>20</result>