Calculate with a simple method: 2+4+6+8+...+96+98+100.
用简便方法计算：2+4+6+8+…+96+98+100．
<gadget id="calculator">2 + 100</gadget>
<output>102</output>

<gadget id="calculator">50 / 2</gadget>
<output>25</output>

<gadget id="calculator">102 * 25</gadget>
<output>2_550</output>

<result>2_550</result>