Calculation: 1+4+9+16+25+...+400=how much.
计算：1+4+9+16+25+…+400=多少．
<gadget id="calculator">20 + 1</gadget>
<output>21</output>

<gadget id="calculator">2 * 20</gadget>
<output>40</output>

<gadget id="calculator">40 + 1</gadget>
<output>41</output>

<gadget id="calculator">41 / 6</gadget>
<output>41/6 = around 6.833333</output>

<gadget id="calculator">20 * 21 * (41/6)</gadget>
<output>2_870</output>

<result>2_870</result>