Xiaohong bought 4 pens and 4 diaries. The pen cost 10.2 yuan and the diary 36.8 yuan. How much is a diary more expensive than a pen? (answer in two ways)
小红买了4支钢笔和4本日记本，买钢笔用去10.2元，买日记本用去36.8元，一本日记本比一支钢笔贵多少元？(用两种方法解答)
<gadget id="calculator">36.8 / 4</gadget>
<output>9.2</output>

<gadget id="calculator">10.2 / 4</gadget>
<output>2.55</output>

<gadget id="calculator">9.2 - 2.55</gadget>
<output>6.65</output>

<result>6.65</result>