A total of 650 chickens are raised in the chicken farm, and the number of hens is 1.6 times that of roosters. How many hens are there in the chicken farm?
养鸡场一共养鸡650只，其中母鸡的只数是公鸡的1.6倍．养鸡场养母鸡多少只？
<gadget id="calculator">1 + 1.6</gadget>
<output>2.6</output>

<gadget id="calculator">650 / 2.6</gadget>
<output>250</output>

<gadget id="calculator">650 - 250</gadget>
<output>400</output>

<result>400</result>