There are 420 hens in Xiaoming's house, and the number of roosters is less than that of hens (1/3). How many fewer roosters are in Xiaoming's house than hens?
小明家有母鸡420只，公鸡的只数比母鸡少(1/3)，小明家有公鸡只数比母鸡少多少只？
<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">420 * (1/3)</gadget>
<output>140</output>

<result>140</result>