1+2+...+8+9+10+9+8+...+2+1=how much.
1+2+…+8+9+10+9+8+…+2+1=多少．
<gadget id="calculator">10 + 1</gadget>
<output>11</output>

<gadget id="calculator">10 / 2</gadget>
<output>5</output>

<gadget id="calculator">11 * 5</gadget>
<output>55</output>

<gadget id="calculator">9 + 1</gadget>
<output>10</output>

<gadget id="calculator">9 / 2</gadget>
<output>9/2 = around 4.5</output>

<gadget id="calculator">10 * (9/2)</gadget>
<output>45</output>

<gadget id="calculator">55 + 45</gadget>
<output>100</output>

<result>100</result>