There are 40 students in class 5 and 2, including 18 girls, and boys account for ((())/(())).
五2班有40人，其中女生18人，男生占女生人数的((())/(()))．
<gadget id="calculator">40 - 18</gadget>
<output>22</output>

<gadget id="calculator">22 / 18</gadget>
<output>11/9 = around 1.222222</output>

<result>11/9 = around 1.222222</result>