diff --git a/src/ikarus.boot b/src/ikarus.boot
index 26ad1ba..0393e24 100644
Binary files a/src/ikarus.boot and b/src/ikarus.boot differ
diff --git a/src/ikarus.numerics.ss b/src/ikarus.numerics.ss
index 6118f74..1f75887 100644
--- a/src/ikarus.numerics.ss
+++ b/src/ikarus.numerics.ss
@@ -2371,3 +2371,57 @@
           (go x eps)]
          [else (error who "~s is not a number" eps)])]
       [else (error who "~s is not a number" x)])))
+
+
+(library (ikarus r6rs-fu div/mod)
+  (export div mod div-and-mod div0 mod0 div0-and-mod0)
+  (import 
+    (except (ikarus) 
+      div mod div-and-mod div0 mod0 div0-and-mod0))
+
+  (define (div-and-mod x y) 
+    (define who 'div-and-mod)
+    (unless (integer? x)
+      (error who "~s is not an integer" x))
+    (unless (and (integer? y) (not (= y 0)))
+      (error who "~s is not an integer" y))
+    (if (> x 0) 
+        (quotient+remainder x y)
+        (if (> y 0) 
+            (let-values ([(q r) (quotient+remainder (- x y) y)])
+              (values q (+ r y)))
+            (let-values ([(q r) (quotient+remainder (+ x y) y)])
+              (values q (- r y))))))
+  
+  (define (div x y) 
+    (let-values ([(n m) (div-and-mod x y)])
+       n))
+  
+  (define (mod x y) 
+    (let-values ([(n m) (div-and-mod x y)])
+       m))
+  
+  (define (div0-and-mod0 x y) 
+    (define who 'div0-and-mod0)
+    (unless (integer? x)
+      (error who "~s is not an integer" x))
+    (unless (and (integer? y) (not (= y 0)))
+      (error who "~s is not an integer" y))
+    (let-values ([(d m) (div-and-mod x y)])
+      (if (> y 0) 
+          (if (< m (/ y 2))
+              (values d m)
+              (values (+ d 1) (- m y)))
+          (if (> m (/ y -2))
+              (values (- d 1) (+ m y))
+              (values d m)))))
+  
+  (define (div0 x y) 
+    (let-values ([(n m) (div0-and-mod0 x y)])
+       n))
+  
+  (define (mod0 x y) 
+    (let-values ([(n m) (div0-and-mod0 x y)])
+       m)))
+  
+
diff --git a/src/makefile.ss b/src/makefile.ss
index cfeb222..565ad9d 100755
--- a/src/makefile.ss
+++ b/src/makefile.ss
@@ -530,6 +530,12 @@
     [modulo                  i r]
     [remainder               i r]
     [quotient+remainder      i r]
+    [div                     i]
+    [mod                     i]
+    [div-and-mod             i]
+    [div0                    i]
+    [mod0                    i]
+    [div0-and-mod0           i]
     [number->string          i r]
     [string->number          i r]
     [flonum->string          i]
diff --git a/src/run-tests.ss b/src/run-tests.ss
index 59e59c3..06639db 100755
--- a/src/run-tests.ss
+++ b/src/run-tests.ss
@@ -4,6 +4,7 @@
         (tests reader)
         (tests bytevectors)
         (tests strings)
+        (tests numbers)
         (tests bignum-to-flonum)
         (tests string-to-number))
 
@@ -26,4 +27,5 @@
 (test-exact-integer-sqrt)
 (test-bignum-to-flonum)
 (test-string-to-number)
+(test-div-and-mod)
 (printf "Happy Happy Joy Joy\n")
diff --git a/src/todo-r6rs.ss b/src/todo-r6rs.ss
index d9d473b..ffc1685 100755
--- a/src/todo-r6rs.ss
+++ b/src/todo-r6rs.ss
@@ -134,10 +134,12 @@
     [cons                                       C ba se]
     [cos                                        C ba se]
     [denominator                                C ba se]
-    [div                                        S ba]
-    [div-and-mod                                S ba]
-    [div0                                       S ba]
-    [div0-and-mod0                              S ba]
+    [div                                        C ba]
+    [mod                                        C ba]
+    [div-and-mod                                C ba]
+    [div0                                       C ba]
+    [mod0                                       C ba]
+    [div0-and-mod0                              C ba]
     [dynamic-wind                               C ba se]
     [eq?                                        C ba se]
     [equal?                                     S ba se]
@@ -177,8 +179,6 @@
     [map                                        C ba se]
     [max                                        C ba se]
     [min                                        C ba se]
-    [mod                                        S ba]
-    [mod0                                       S ba]
     [nan?                                       S ba]
     [negative?                                  C ba se]
     [not                                        C ba se]