There are 100 geese in the farm, which is the number of ducks (1/4), and the number of ducks is the number of chickens (4/9), how many chickens are kept.
饲养场养鹅100只，是养鸭只数的(1/4)，养鸭只数又是养鸡只数的(4/9)，饲养鸡多少只．
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">4 / 9</gadget>
<output>4/9 = around 0.444444</output>

<gadget id="calculator">100 / (1/4) / (4/9)</gadget>
<output>900</output>

<result>900</result>