1+11*111-1111=how much.
1+11*111-1111=多少．
<gadget id="calculator">11 * 111</gadget>
<output>1_221</output>

<gadget id="calculator">1_221 - 1_111</gadget>
<output>110</output>

<gadget id="calculator">1 + 110</gadget>
<output>111</output>

<result>111</result>