Xiao Ming said: "I make 5 pages of exercise books every day, which takes (10/21) hours, how many hours does it take to make one page of exercise books.
小明说："我每天做5页练习册，共用(10/21)小时，做一页练习册要用多少小时．
<gadget id="calculator">4 / 21</gadget>
<output>4/21 = around 0.190476</output>

<gadget id="calculator">(4/21) / 5</gadget>
<output>4/105 = around 0.038095</output>

<result>4/105 = around 0.038095</result>