3+0*3-0/3=how many
3+0*3-0/3=多少
<gadget id="calculator">0 * 3</gadget>
<output>0</output>

<gadget id="calculator">0 / 3</gadget>
<output>0</output>

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

<gadget id="calculator">3 + 0</gadget>
<output>3</output>

<result>3</result>