There are 45 students in Class 51, and boys account for 4/9 of the whole class, so how many girls are there?
五1班有45个学生，男生占全班人数的(4/9)，则女生有多少人．
<gadget id="calculator">4 / 9</gadget>
<output>4/9 = around 0.444444</output>

<gadget id="calculator">45 * (4/9)</gadget>
<output>20</output>

<gadget id="calculator">45 - 20</gadget>
<output>25</output>

<result>25</result>