This year, my mother is 28 years old, and Xiaoming is 7 years old. How many years ago, my mother's age was 8 times that of Xiaoming's.
今年妈妈的年龄28岁，小明7岁，多少年前妈妈的年龄是小明的8倍．
<gadget id="calculator">7 * 8</gadget>
<output>56</output>

<gadget id="calculator">56 - 28</gadget>
<output>28</output>

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

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

<result>4</result>