The total length of China's mainland coastline is about 18,000,000 kilometers, and 18,000,000 is composed of how many one million.
中国的大陆海岸线总长约为18000000千米，18000000是由多少个一百万组成的．
<gadget id="calculator">10 + 8</gadget>
<output>18</output>

<result>18</result>