The school held a charity fundraising event. The first and second grades raised a total of 18,000 yuan, of which the second grade raised 25% more than the first grade, so how much more was the second grade than the first grade?
学校举行献爱心募捐活动，一年级和二年级共募捐1.8万元，其中二年级比一年级多募捐二成五，那么二年级比一年级多募捐多少万元？
<gadget id="calculator">25 / 100</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 + 1 + (1/4)</gadget>
<output>9/4 = around 2.25</output>

<gadget id="calculator">1.8 / (9/4)</gadget>
<output>0.8</output>

<gadget id="calculator">0.8 * (1/4)</gadget>
<output>0.2</output>

<result>0.2</result>