Add 3 to a number, multiply by 3, and divide by 3, the result is still 3. What is this number?
一个数加上3，再乘3，然后除以3，结果仍是3．这个数是多少．
<gadget id="calculator">3 / 3</gadget>
<output>1</output>

<gadget id="calculator">3 * 1</gadget>
<output>3</output>

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

<result>0</result>