A primary school has 600 students, 55% of whom are boys. How many girls are there?
一所小学有学生600人，其中55%是男生．女生有多少人？
<gadget id="calculator">55 / 100</gadget>
<output>11/20 = around 0.55</output>

<gadget id="calculator">1 - (11/20)</gadget>
<output>9/20 = around 0.45</output>

<gadget id="calculator">600 * (9/20)</gadget>
<output>270</output>

<result>270</result>