Simple operation: 11*11+11*11-11*11.
简便运算：11*11+11*11-11*11．
<gadget id="calculator">11 * 11</gadget>
<output>121</output>

<gadget id="calculator">121 - 121</gadget>
<output>0</output>

<gadget id="calculator">121 + 0</gadget>
<output>121</output>

<result>121</result>