The father is 35 years old this year, and the son is 8 years old this year. How old are they together 15 years later?
爸爸今年35岁，儿子今年8岁，15年后，他们俩共多少岁．
<gadget id="calculator">35 + 15</gadget>
<output>50</output>

<gadget id="calculator">15 + 8</gadget>
<output>23</output>

<gadget id="calculator">50 + 23</gadget>
<output>73</output>

<result>73</result>