Uncle Zhang raised 200 geese, and the number of geese was less than that of ducks (1/5). How many ducks do you have?
张大爷养了200只鹅，鹅的只数比鸭少(1/5)．养了多少只鸭？
<gadget id="calculator">1 / 5</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">200 / (4/5)</gadget>
<output>250</output>

<result>250</result>