Last year Xiao Ming was 28 years younger than his father, but this year his father is 8 times younger than Xiao Ming. How old is Xiao Ming?
去年小明比他爸爸小28岁，今年爸爸的年龄是小明的8倍．小明今年多少岁？
<gadget id="calculator">8 - 1</gadget>
<output>7</output>

<gadget id="calculator">28 / 7</gadget>
<output>4</output>

<result>4</result>