The students made 20 red flags and 30 yellow flags, how much more yellow flags were made than red flags
同学们做了20面红旗，30面黄旗，做的黄旗比红旗多多少
<gadget id="calculator">30 - 20</gadget>
<output>10</output>

<gadget id="calculator">10 / 20</gadget>
<output>1/2 = around 0.5</output>

<result>1/2 = around 0.5</result>