You can use the parse and format float calls documented here to convert to and from floats respectively.
Hope this helps
Yes you would need a microflow to do so.
In the image beneath you can see how you can parse a String parameter to a Float variable. If you have any questions feel free to ask them.
P.S.: I would recommend using a Decimal instead of a Float as Floats are deprecated.
Thanks for answer.
But where can i parse it and how to do this (in an microflow?)