I am 38 years old, 4 years younger than my grandfather's age (3/5). How old is grandpa this year?
我今年38岁，比爷爷的年龄的(3/5)小4岁．爷爷今年多大了？
<gadget id="calculator">38 + 4</gadget>
<output>42</output>

<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">42 / (3/5)</gadget>
<output>70</output>

<result>70</result>