Xiao Ming is 9 years old this year, and his grandfather is 73 years old this year. When his grandfather is five times Xiao Ming's age, how old is Xiao Ming?
小明今年9岁，爷爷今年73岁，当爷爷年龄是小明年龄的5倍时，小明正好多少岁．
<gadget id="calculator">73 - 9</gadget>
<output>64</output>

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

<gadget id="calculator">64 / 4</gadget>
<output>16</output>

<result>16</result>