There are 40 chickens and rabbits with 112 legs. How many chickens are there?
鸡、兔共有40只，共有112只脚，鸡有多少只．
<gadget id="calculator">40 * 4</gadget>
<output>160</output>

<gadget id="calculator">160 - 112</gadget>
<output>48</output>

<gadget id="calculator">4 - 2</gadget>
<output>2</output>

<gadget id="calculator">48 / 2</gadget>
<output>24</output>

<result>24</result>