In the morning, Xiao Ming did his summer homework for an hour and a half. When his mother was checking the homework, she pointed to a subtraction formula and said, "Xiao Ming, you were careless again. You wrote 9 for the 6 in the subtrahend, and 9 for the tens place." 9 was wrongly written as 6." Xiao Ming's calculated difference is 5.7, so what is the correct answer to this question?
上午小明做了一个半小时的暑假作业，妈妈检查作业时，指着一道减法算式说："小明，又粗心了，你把被减数个位上的6错写成了9，把十分位上的9错写成了6．"小明算得的差是5.7，那么，这道题的正确答案是多少？
<gadget id="calculator">9 - 6</gadget>
<output>3</output>

<gadget id="calculator">5.7 - 3</gadget>
<output>2.7</output>

<gadget id="calculator">0.9 - 0.6</gadget>
<output>0.3</output>

<gadget id="calculator">2.7 + 0.3</gadget>
<output>3</output>

<result>3</result>