There are 250 boys in an elementary school, and 100 fewer girls than boys, how many more girls than boys in this school?
一所小学有男生250人，女生比男生的2倍少100人，这所学校的女生比男生多多少人？
<gadget id="calculator">250 * 2</gadget>
<output>500</output>

<gadget id="calculator">500 - 100</gadget>
<output>400</output>

<gadget id="calculator">400 - 250</gadget>
<output>150</output>

<result>150</result>