2010*2011-2009*2012=how much.
2010*2011-2009*2012=多少．
<gadget id="calculator">2_010 * 2_011</gadget>
<output>4_042_110</output>

<gadget id="calculator">2_009 * 2_012</gadget>
<output>4_042_108</output>

<gadget id="calculator">4_042_110 - 4_042_108</gadget>
<output>2</output>

<result>2</result>