Beibei’s money to buy a 5.9-yuan notebook is 0.6 yuan short, and he buys a 4.8-yuan notebook, and the remaining money just buys a ballpoint pen. How much is this ballpoint pen?
贝贝的钱买一本5.9元笔记本差0.6元，他买一本4.8元的，剩下的钱正好买一只圆珠笔，这只圆珠笔多少钱？
<gadget id="calculator">5.9 - 0.6 - 4.8</gadget>
<output>0.5</output>

<result>0.5</result>