When I select "Edit a copy" I can't change serving properly (and other issues).

Sometimes when I scan something it comes up with wrong values, so I select "edit a copy" and try to fix them, but have run across a bug. If, for example, the serving was "10 pieces" and I try to change it to "12 slices", the (Android) app retains the "10", so the new serving shows as "10 12 slices", which messes up other calculations. I cannot seem to get rid of it, so I end up entering everything from scratch.

Related to this, it is good that you are evidently storing the numerical multiplier separately, although it is unfortunate that you do not make proper use of it: I should be able to enter "1 slice" and have it know that I mean 1/12 of a serving, instead of having to enter 0.083 of 12 slices. This gets complicated when I have 1/3 of a 284ml can of soup, say, for which the serving size is 125ml ... I need a calculator to figure out what fraction of a serving I ate, when I should be able to just enter how many ml I had and the app should figure it out.

Which brings me to another peeve of mine, fraction support: the website has it, why not the app? Simply entering 284/3 ml instead of 0.757 x 125ml servings is my dream!

Thanks for your attention, I really hope you can address these issues, which would immensely improve usability.