The uncle said to Xiao Ming: "My age 15 years ago was the same as your age 6 years later. 7 years ago, my age was 8 times your age." Please think about it, how old is Xiao Ming this year? How many
大叔对小明说："我15年前的年龄和你6年后的年龄相等，7年前，我的年龄是你的年龄的8倍，"请想一想，小明今年多少岁？多少
<gadget id="calculator">15 + 6</gadget>
<output>21</output>

<gadget id="calculator">8 - 1</gadget>
<output>7</output>

<gadget id="calculator">21 / 7</gadget>
<output>3</output>

<gadget id="calculator">7 + 3</gadget>
<output>10</output>

<result>10</result>