Calculation: 1+2+3+4+...+2014+2015=how much.
计算：1+2+3+4+…+2014+2015=多少．
<gadget id="calculator">1 + 2_015</gadget>
<output>2_016</output>

<gadget id="calculator">2_015 / 2</gadget>
<output>2_015/2 = around 1_007.5</output>

<gadget id="calculator">2_016 * (2_015/2)</gadget>
<output>2_031_120</output>

<result>2_031_120</result>