This also occurs whenever a text box is parsed, for example typing 1.0 + a, or copying and pasting a similar expression.
This is due to the parser used, JEP, interpreting every number whether it be written 1 or 1.0, as 1.0. Therefore, there is no way to tell how the number was entered.
To provide a workaround for this the next release (v0.7.7) will include the option for decimal numbers which can be expressed as integers to be converted. e.g. 1.0 becomes 1, and 1.5 remains as 1.5 (how DragMath currently works). Or all numbers to be displayed as decimal numbers, therefore, 1 becomes 1.0, and 1.5 remains as 1.5.