When subtracting 487 from a number, Xiao Ming swapped the hundreds and tens digits of the subtrahend, and the result is 172, so what is the correct difference?
一个数减去487，小明将被减数的百位和十位上的数字互换了，结果的172，那么正确的差是？
<gadget id="calculator">569 - 487</gadget>
<output>82</output>

<result>82</result>