When Xiao Ming calculated, he regarded the second addend 1.2 among the two addends as 2.1, and the result was 4.05. Please help Xiao Ming calculate the correct result.
小明在计算时，把两个加数中的第二个加数1.2看成了2.1计算，结果得出4.05．请你帮小明计算出正确的结果．
<gadget id="calculator">4.05 - 2.1</gadget>
<output>1.95</output>

<gadget id="calculator">1.95 + 1.2</gadget>
<output>3.15</output>

<result>3.15</result>