2010*2009-2011*2008．
2010*2009-2011*2008．
<gadget id="calculator">2_010 * 2_009</gadget>
<output>4_038_090</output>

<gadget id="calculator">2_011 * 2_008</gadget>
<output>4_038_088</output>

<gadget id="calculator">4_038_090 - 4_038_088</gadget>
<output>2</output>

<result>2</result>