Uncle Li's family originally raised 300 chickens, accounting for 25% of the total number of chickens and ducks. Later, some chickens were bought, and the number of chickens was 120% of that of ducks. How many chickens did you buy?
李大爷家原来养鸡300只，占鸡和鸭总数的25%．后来又买来了一些鸡，这时鸡的只数是鸭的120%．买来的鸡有多少只？
<gadget id="calculator">25 / 100</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">300 / (1/4)</gadget>
<output>1_200</output>

<gadget id="calculator">1_200 - 300</gadget>
<output>900</output>

<gadget id="calculator">120 / 100</gadget>
<output>6/5 = around 1.2</output>

<gadget id="calculator">900 * (6/5)</gadget>
<output>1_080</output>

<gadget id="calculator">1_080 - 300</gadget>
<output>780</output>

<result>780</result>