9+11+13+15+17+19+21+23+...+51=how much.
9+11+13+15+17+19+21+23+…+51=多少．
<gadget id="calculator">9 + 51</gadget>
<output>60</output>

<gadget id="calculator">51 - 9</gadget>
<output>42</output>

<gadget id="calculator">42 / 2</gadget>
<output>21</output>

<gadget id="calculator">21 + 1</gadget>
<output>22</output>

<gadget id="calculator">22 / 2</gadget>
<output>11</output>

<gadget id="calculator">60 * 11</gadget>
<output>660</output>

<result>660</result>