The school originally had 2,400 books, but this semester has increased to 3,000. What percentage is the increase?
学校原有图书2400本，这学期增加到3000本，增加了百分之几？
<gadget id="calculator">3_000 - 2_400</gadget>
<output>600</output>

<gadget id="calculator">600 / 2_400</gadget>
<output>1/4 = around 0.25</output>

<result>1/4 = around 0.25</result>