I don't have the book and can't find it, but in case it's useful here are some closely related finds
BINAR FORTH FLOATING POINT REFERENCE 60 page pdf
Quote:
This floating point package and its documentation are derived from: Koopman, P., Forth Floating Point and Integer Math, Mountain View Press, 1985. That book and the associated code were copyrighted and then placed into the public domain. However, the code and documentation here are substantially refined
Forth Dimensions vol 4 number 1 "Math edition" has articles on both fixed and floating point
TRANSCENDENTAL FUNCTIONS short article by Koopman in Forth Dimensions Vol 9 No 4
Worldcat entry
https://search.worldcat.org/title/14224155