The younger brother is 3 years old this year, and the older brother is 9 years old this year. How old is the older brother than the younger brother?
弟弟今年3岁，哥哥今年9岁，哥哥比弟弟大几岁？
<gadget id="calculator">9 - 3</gadget>
<output>6</output>

<result>6</result>