Aunt Zhang raised 27 chickens. There are 8 roosters, how many hens are there? Answer: How many hens are there?
张大妈养了27只鸡．其中公鸡有8只，母鸡有多少只？答：母鸡有多少只．
<gadget id="calculator">27 - 8</gadget>
<output>19</output>

<result>19</result>