There is a number, divided by 4, added to 4, subtracted from 4, exactly equal to 4, what is this number?
有一个数，除以4，加上4，减去4，正好等于4，这个数是多少．
<gadget id="calculator">4 + 4</gadget>
<output>8</output>

<gadget id="calculator">8 - 4</gadget>
<output>4</output>

<gadget id="calculator">4 * 4</gadget>
<output>16</output>

<result>16</result>