The father is 35 years old this year, the age of the son is the father's (1/7), and in another 5 years, the son's age is the father's ((())/(())).
今年爸爸35岁，儿子的年龄是爸爸的(1/7)，再过5年，儿子的年龄是爸爸的((())/(()))．
<gadget id="calculator">1 / 7</gadget>
<output>1/7 = around 0.142857</output>

<gadget id="calculator">35 * (1/7)</gadget>
<output>5</output>

<gadget id="calculator">5 + 5</gadget>
<output>10</output>

<gadget id="calculator">35 + 5</gadget>
<output>40</output>

<gadget id="calculator">10 / 40</gadget>
<output>1/4 = around 0.25</output>

<result>1/4 = around 0.25</result>