Teacher Li wants to use 100 yuan to buy prizes for the class. Each pen is 4.5 yuan, and each notepad is 3.1 yuan. Teacher Li bought 5 pens. How many notebooks can I buy with the remaining money?
李老师要用100元为班级买奖品，钢笔每支4.5元，便签本每本3.1元，李老师买了5支钢笔，剩下的钱还可以买多少本便签本？
<gadget id="calculator">5 * 4.5</gadget>
<output>22.5</output>

<gadget id="calculator">100 - 22.5</gadget>
<output>77.5</output>

<gadget id="calculator">77.5 / 3.1</gadget>
<output>25</output>

<result>25</result>