Calculation: 1+2-3+4+5-6+7+8-9+...+97+98-99.
计算：1+2-3+4+5-6+7+8-9+…+97+98-99．
<gadget id="calculator">98 - 99</gadget>
<output>-1</output>

<gadget id="calculator">97 + (-1)</gadget>
<output>96</output>

<gadget id="calculator">0 + 96</gadget>
<output>96</output>

<gadget id="calculator">33 / 2</gadget>
<output>33/2 = around 16.5</output>

<gadget id="calculator">96 * (33/2)</gadget>
<output>1_584</output>

<result>1_584</result>