Good day, (define (test a) (printf "~%~s" a)) (test (/ (+ 5 -10) 10)) ;; display -1.5 (test (/ (+ 8 -10) 10)) ;; display -1.8 The answer should always be between -1.0 and 1.0 I use DrScheme, version 200alpha12, english with windows XP; pentium iv; Andre Mayers