Xiao Rong is 9 years old this year, and his mother is 37 years old this year. After 10 years, how much older will his mother be than Xiao Rong?
小荣今年9岁，妈妈今年37岁，10年之后，妈妈比小荣大多少岁．
<gadget id="calculator">37 - 9</gadget>
<output>28</output>

<result>28</result>