The ancient Chinese mathematician Zu Chongzhi was born in 429 AD and died in 500 AD. How old was he?
我国古代数学家祖冲之出生于公元429年，去世于公元500年，他活了多少岁．
<gadget id="calculator">500 - 429</gadget>
<output>71</output>

<result>71</result>