Xiao Ming brought 25 yuan to buy stationery. It cost 15.8 yuan to buy a pen, and 4.5 yuan to buy a notebook. How much money is left?
小明带了25元钱买文具．买笔花了15.8元，买本子花了4.5元，还剩下多少元．
<gadget id="calculator">15.8 + 4.5</gadget>
<output>20.3</output>

<gadget id="calculator">25 - 20.3</gadget>
<output>4.7</output>

<result>4.7</result>