There are 30 boys, and girls belong to boys (1/3), how many girls are there?
男生30人，女生是男生的(1/3)，女生有多少人？
<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">30 * (1/3)</gadget>
<output>10</output>

<result>10</result>