The total area of the earth's surface is 510 million square kilometers, of which the ocean area is 362 million square kilometers. By how many billion square kilometers is the ocean area greater than the land area?
地球表面的总面积是5.1亿平方千米，其中海洋面积是3.62亿平方千米．海洋面积比陆地面积多多少亿平方千米？
<gadget id="calculator">5.1 - 3.61</gadget>
<output>1.49</output>

<gadget id="calculator">3.61 - 1.49</gadget>
<output>2.12</output>

<result>2.12</result>