Uncle Zhang raised 200 geese, and the number of ducks was 60% less than that of geese. How many ducks did he raise?
张大爷养了200只鹅，鸭的只数比鹅少60%，养了多少只鸭？
<gadget id="calculator">60 / 100</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">1 - (3/5)</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">200 * (2/5)</gadget>
<output>80</output>

<result>80</result>