Xiao Ming is 12 years old this year, and his father is 40 years old. A few years ago, Dad's age was five times that of Xiao Ming's. What do you think is the sum of the ages of the father and son?
今年小明12岁，爸爸40岁．几年前，爸爸的年龄是小明的5倍，你认为这时父子两人年龄的和是多少岁？
<gadget id="calculator">40 - 12</gadget>
<output>28</output>

<gadget id="calculator">5 - 1</gadget>
<output>4</output>

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

<gadget id="calculator">5 + 1</gadget>
<output>6</output>

<gadget id="calculator">7 * 6</gadget>
<output>42</output>

<result>42</result>