Dad is 34 years old and his son is 9 years old. 4 years ago, the age of the father was how many times the age of the son.
爸爸今年34岁，儿子今年9岁．4年前，爸爸的年龄是儿子的多少倍．
<gadget id="calculator">34 - 4</gadget>
<output>30</output>

<gadget id="calculator">9 - 4</gadget>
<output>5</output>

<gadget id="calculator">30 / 5</gadget>
<output>6</output>

<result>6</result>