diff --git a/04-giant-squid/code.scm b/04-giant-squid/code.scm
index 9216af8..d8e58dd 100644
--- a/04-giant-squid/code.scm
+++ b/04-giant-squid/code.scm
@@ -2,10 +2,6 @@
 
 (load "../common.scm")
 
-; returns numbers 0 to 9 from ascii character
-(define (char->number c)
-  (- (char->integer c) 48)) ; 48 is ASCII's number zero
-
 ; returns a number from two characters
 ; ex: '0' and '9' => 9
 ;     ' ' and '6' => 6
diff --git a/common.scm b/common.scm
index e839719..e21f5c2 100644
--- a/common.scm
+++ b/common.scm
@@ -7,3 +7,8 @@
 	[(char=? c #\,) (loop (cons n draws) 0)]
 	[(char-whitespace? c) (reverse (cons n draws))]
 	[else (loop draws (+ (* n 10) (string->number (string c))))]))))
+
+; returns numbers 0 to 9 from ascii character
+(define (char->number c)
+  (- (char->integer c) 48)) ; 48 is ASCII's number zero
+