Lili went to the bookstore to buy a notebook, and she bought a notebook for 6.8 yuan, which was 0.7 yuan short, so she had to buy a notebook for 4.5 yuan, and the remaining money just bought a ballpoint pen. How much is this ballpoint pen?
丽丽到书店买笔记本，买6.8元一本的，差0.7元，她只好买4.5元一本的，剩下的钱正好买了一枝圆珠笔．这枝圆珠笔多少钱？
<gadget id="calculator">6.8 - 0.7 - 4.5</gadget>
<output>1.6</output>

<result>1.6</result>