Uncle Li’s family raises 90 chickens, and the number of ducks is less than that of chickens (5/9). How many fewer ducks are there than chickens?
李大伯家养鸡90只，养的鸭比鸡少(5/9)，养的鸭比鸡少多少只？
<gadget id="calculator">5 / 9</gadget>
<output>5/9 = around 0.555556</output>

<gadget id="calculator">90 * (5/9)</gadget>
<output>50</output>

<result>50</result>