When A performs division, he regards the dividend 2090 as 2009, and the result reduces the quotient by 27, but the remainder remains unchanged. What is the divisor?
甲做除法时将被除数2090看成2009，结果使得商减少了27，而余数没有变，则除数是多少．
<gadget id="calculator">2_090 - 2_009</gadget>
<output>81</output>

<gadget id="calculator">81 / 27</gadget>
<output>3</output>

<result>3</result>