The school has planted 300 poplar trees, and the number of poplar trees is 1/3 that of willow trees. How many willow trees have been planted in the school?
学校栽了300棵杨树，杨树的棵数是柳树的(1/3)，学校栽了多少棵柳树？
<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">300 / (1/3)</gadget>
<output>900</output>

<result>900</result>