There are 45 students in class one of six years, and girls account for (4/9). How many girls are there?
六年一班有学生45人，女生占(4/9)．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>

<result>20</result>