The chicken farm raised 2,400 chickens this year, an increase of (1/4) compared to last year. How many chickens were raised last year?
养鸡厂今年养鸡2400只，比去年增加了(1/4)，去年养鸡多少只？
<gadget id="calculator">1 / 4</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>