The cattle farm raised 120 cattle this year, an increase of 20% over last year. How many cattle were raised last year?
养牛场今年养牛120头，比去年增加20%，去年养牛多少头？
<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 + (1/5)</gadget>
<output>6/5 = around 1.2</output>

<gadget id="calculator">120 / (6/5)</gadget>
<output>100</output>

<result>100</result>