странный вывод результата

(defun string-to-number (n)
  (car (list (read-from-string n))))

(defun degrees-minutes-seconds-to-radians (d m s)
  (+ (* (string-to-number d) (/ pi 180))
     (* (string-to-number m) (/ pi (* 180 60)))
     (* (string-to-number s) (/ pi (* 180 60 60)))
     ))

;;;(let* ((n 4)
   ;;;      (m (expt 10 n)))
      ;;;(/ (fround 0.2398476566 (/ 1 m)) m))

;;; Round a flout number to required number of digits
(defun my-round (x digits)
(let* ((n (string-to-number digits))
         (m (expt 10 n)))
      (/ (fround x (/ 1 m)) m)))


(defun dms ()
  (with-ltk ()
    (let* ((window (make-instance 'frame))
	   #-:tk84
	 ;;;; Explanation
	 (fcriteria (make-instance 'frame :master window))
	 (criteria (make-instance 'label
				  :master fcriteria
				  :width 60
				  :text "rad = aº * (π / 180) + a' * (π / (180 * 60) + a'' * (π / (180 * 60 * 60))"))
	   (fdigits (make-instance 'frame :master window))
	   (before-digits (make-instance 'label
					 :master fdigits
					 :text "Округлить до "))
	   (e-digits (make-instance 'entry
				    :master fdigits
				    :width 1))
	   (after-digits (make-instance 'label
					:master fdigits
					:text " знаков после запятой"))
	 ;;;; ENTER DATA
(fdms (make-instance 'frame :master window))
(e-degrees (make-instance 'entry
			  :master fdms
			  :width 3))
(e-minutes (make-instance 'entry
			  :master fdms
			  :width 2))
(e-seconds (make-instance 'entry
			  :master fdms
			  :width 2))
(l-d (make-instance 'label
		    :master fdms
		    :text "º "))
(l-m (make-instance 'label
		    :master fdms
		    :text "' "))
(l-s (make-instance 'label
		    :master fdms
		    :text "''"))
(l1 (make-instance 'label
		   :master fdms
		   :text " = "))
(l2 (make-instance 'label
		   :master fdms
		   :text " rad"))
a
r
rslt
(b1 (make-instance 'button
		   :master window
		   :text "Run"
		   :command (lambda ()
			      (setf
			       a (degrees-minutes-seconds-to-radians
				  (text e-degrees)
				  (text e-minutes)
				  (text e-seconds)))
			      (setf r (my-round a (text e-digits)))
			      (setf (text rslt) r)))))

(setf rslt (make-instance 'label :master fdms :text 0))

(pack window)
(pack fcriteria)
(pack criteria)
(pack fdigits)
(pack before-digits :side :left)
(pack e-digits :side :left)
(pack after-digits :side :left)
(pack fdms)
(pack e-degrees :side :left)
(pack l-d :side :left)
(pack e-minutes :side :left)
(pack l-m :side :left)
(pack e-seconds :side :left)
(pack l-s :side :left)
(pack l1 :side :left)
(pack rslt :side :left)
(pack l2 :side :left)
(pack b1))))