The total steel consumption of "Bird's Nest" is about 110,000 tons, which is 5,000 tons more than 2.5 times the steel consumption of the external structure. Q How many tons of steel is used for the external structure of the "Bird's Nest"?
"鸟巢"总用钢量约为11万吨，比外部结构用钢量的2.5倍还多0.5万吨．问"鸟巢"的外部结构大约用钢量多少万吨？
<gadget id="calculator">11 - 0.5</gadget>
<output>10.5</output>

<gadget id="calculator">10.5 / 2.5</gadget>
<output>4.2</output>

<result>4.2</result>