Grandpa is 80 years old this year, father's age is grandpa's (3/5), and Xiaoming's age happens to be father's (1/4). How old is Xiao Ming?
爷爷今年80岁，爸爸的年龄是爷爷的(3/5)，小明的年龄恰巧是爸爸的(1/4)．小明今年多少岁？
<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

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

<gadget id="calculator">80 * (3/5) * (1/4)</gadget>
<output>12</output>

<result>12</result>