A certain experimental primary school had 2,400 students last year, an increase of 25% compared to the previous year. How many students did this primary school have in the previous year?
某实验小学去年2400人，比前年人数增加了二成五，这个小学前年有多少人？
<gadget id="calculator">25 / 100</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 + (1/4)</gadget>
<output>5/4 = around 1.25</output>

<gadget id="calculator">2_400 / (5/4)</gadget>
<output>1_920</output>

<result>1_920</result>