The boys in class 1 of the sixth grade account for the whole class (2/5), then the girls make up the total number of the class.
六年级1班男生是全班人数的(2/5)，则女生是全班总人数的多少．
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 - (2/5)</gadget>
<output>3/5 = around 0.6</output>

<result>3/5 = around 0.6</result>