The 2010 Shanghai World Expo (Expo2010) is the 41st World Expo. The 6-month exhibition attracted a record-breaking nearly 70 million visitors, of which the local population accounted for 30%. How many million foreign visitors will there be?
2010年上海世博会(Expo2010)是第41届世界博览会，为期6个月的展览吸引了创纪录近7000万的参观者，其中本地人口占30%，则外来客流量达到多少万？
<gadget id="calculator">30 / 100</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">1 - (3/10)</gadget>
<output>7/10 = around 0.7</output>

<gadget id="calculator">7_000 * (7/10)</gadget>
<output>4_900</output>

<result>4_900</result>