In the shoe store, there are 270 pairs of adult shoes, which is twice as many as children's shoes and 10 pairs less. How many pairs of children's shoes are there?
鞋店里，成人鞋有270双，是儿童鞋的两倍少10双．儿童鞋有多少双？
<gadget id="calculator">270 + 10</gadget>
<output>280</output>

<gadget id="calculator">280 / 2</gadget>
<output>140</output>

<result>140</result>