Calculation: (251/(2008*2009))+(251/(2009*2010))=how much.
计算：(251/(2008*2009))+(251/(2009*2010))=多少．
<gadget id="calculator">2_008 * 2_009</gadget>
<output>4_034_072</output>

<gadget id="calculator">251 / 4_034_072</gadget>
<output>1/16_072 = around 0.000062</output>

<gadget id="calculator">2_009 * 2_010</gadget>
<output>4_038_090</output>

<gadget id="calculator">251 / 4_038_090</gadget>
<output>251/4_038_090 = around 0.000062</output>

<gadget id="calculator">(1/16_072) + (251/4_038_090)</gadget>
<output>1/8_040 = around 0.000124</output>

<result>1/8_040 = around 0.000124</result>