Add 7 to a number, multiply by 7, divide by 7, the result is 7, what is the number?
一个数加上7，乘以7，除以7，结果等于7，这个数是多少．
<gadget id="calculator">7 / 7</gadget>
<output>1</output>

<gadget id="calculator">7 * 1</gadget>
<output>7</output>

<gadget id="calculator">7 - 7</gadget>
<output>0</output>

<result>0</result>