(101+103+...+199)-(90+92+...+188)=how much.
(101+103+…+199)-(90+92+…+188)=多少．
<gadget id="calculator">199 - 188</gadget>
<output>11</output>

<gadget id="calculator">199 - 101</gadget>
<output>98</output>

<gadget id="calculator">98 / 2</gadget>
<output>49</output>

<gadget id="calculator">49 + 1</gadget>
<output>50</output>

<gadget id="calculator">11 * 50</gadget>
<output>550</output>

<result>550</result>