The combined age of Xiaogang and Xiaoli this year is 28 years old. Xiaogang is 4 years younger than Xiaoli. How old is Xiaogang?
小刚和小丽今年的年龄和是28岁，小刚比小丽小4岁，小刚今年几岁？
<gadget id="calculator">28 - 4</gadget>
<output>24</output>

<gadget id="calculator">24 / 2</gadget>
<output>12</output>

<result>12</result>