Xiaogang is 10 years old, Xiaohong is 9 years old, Xiaofang is 6 years old, and Xiaowen is 7 years old. What is their average age?
小刚10岁，小红9岁，小方6岁，小文7岁，他们的平均年龄是多少岁．
<gadget id="calculator">10 + 9 + 6 + 7</gadget>
<output>32</output>

<gadget id="calculator">32 / 4</gadget>
<output>8</output>

<result>8</result>