Observation and calculation: (2005/1003)*(2/2007)+(2005/2006)*(2005/2007)+(2005/3009)*(3/2007)=how much.
观察巧算：(2005/1003)*(2/2007)+(2005/2006)*(2005/2007)+(2005/3009)*(3/2007)=多少．
<gadget id="calculator">2_005 / 1_003</gadget>
<output>2_005/1_003 = around 1.999003</output>

<gadget id="calculator">2 / 2_007</gadget>
<output>2/2_007 = around 0.000997</output>

<gadget id="calculator">(2_005/1_003) * (2/2_007)</gadget>
<output>4_010/2_013_021 = around 0.001992</output>

<gadget id="calculator">2_005 / 2_006</gadget>
<output>2_005/2_006 = around 0.999501</output>

<gadget id="calculator">2_005 / 2_007</gadget>
<output>2_005/2_007 = around 0.999003</output>

<gadget id="calculator">(2_005/2_006) * (2_005/2_007)</gadget>
<output>4_020_025/4_026_042 = around 0.998505</output>

<gadget id="calculator">2_005 / 3_009</gadget>
<output>2_005/3_009 = around 0.666334</output>

<gadget id="calculator">3 / 2_007</gadget>
<output>1/669 = around 0.001495</output>

<gadget id="calculator">(2_005/3_009) * (1/669)</gadget>
<output>2_005/2_013_021 = around 0.000996</output>

<gadget id="calculator">(4_010/2_013_021) + (4_020_025/4_026_042) + (2_005/2_013_021)</gadget>
<output>4_032_055/4_026_042 = around 1.001494</output>

<result>4_032_055/4_026_042 = around 1.001494</result>