Naughty is going to buy a copy of "Encyclopedia of Knowledge". The price of this book is 48.6 yuan. Naughty has 2.5 yuan of pocket money every day. He decided to save all the pocket money in April to buy this book. How much money is left after buying this book?
淘气准备买一本《百科知识大全》，这本书的价格为48.6元．淘气每天有2.5元的零花钱，他决定把4月份的零花钱全部攒下来买这本书，买完这本书还剩多少钱？
<gadget id="calculator">2.5 * 30</gadget>
<output>75</output>

<gadget id="calculator">75 - 48.6</gadget>
<output>26.4</output>

<result>26.4</result>