There are 1200 chickens, 20% less than ducks. How many ducks are there?
鸡养了1200只，比鸭少20%．鸭养了多少只？
<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 - (1/5)</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">1_200 / (4/5)</gadget>
<output>1_500</output>

<result>1_500</result>