There are about 270 volcanoes in China's Inner Mongolia Plateau, 50 more than the total number of volcanoes in the country (1/3). How many volcanoes are there in the country?
我国内蒙古高原约有火山270座，比全国的火山总数的(1/3)还多50座．全国的火山大约有多少座？
<gadget id="calculator">270 - 50</gadget>
<output>220</output>

<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">220 / (1/3)</gadget>
<output>660</output>

<result>660</result>