There are 40 students in a class, please make up at least three questions about fractions.
一个班级有40名学生，请你编出至少三道有关几分之几的题目．
<gadget id="calculator">40 - 22</gadget>
<output>18</output>

<gadget id="calculator">18 / 22</gadget>
<output>9/11 = around 0.818182</output>

<result>9/11 = around 0.818182</result>