When Ma Xiaohu calculates an addition formula, he regards the 3 in the tenth place of one addend as 5, and the 5 in the hundredth place of the other addend as 3. How much is the difference between the calculated result and the correct result? ．
马小虎在计算一道加法算式时，把一个加数的十分位上的3看成了5，另一个加数的百分位上的5看成了3，这样算出来的结果与正确结果相差多少．
<gadget id="calculator">0.5 - 0.3</gadget>
<output>0.2</output>

<gadget id="calculator">0.05 - 0.03</gadget>
<output>0.02</output>

<gadget id="calculator">0.2 - 0.02</gadget>
<output>0.18</output>

<result>0.18</result>