diff --git a/scaffold/tests/60-math.c b/scaffold/tests/60-math.c
index 05444d31..d3d17a5c 100644
--- a/scaffold/tests/60-math.c
+++ b/scaffold/tests/60-math.c
@@ -18,6 +18,7 @@
  * along with Mes.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include <limits.h>
 #include <stdio.h>
 #include <string.h>
 
@@ -146,5 +147,30 @@ test ()
   puts ("t: 0x11 == 3\n");
   if (0x11 != 17) return 32;
 
+  puts ("t: i = INT_MAX\n");
+  i = INT_MAX;
+
+  if (strcmp ("2147483647", itoa (i)))
+    return 33;
+
+  puts ("t: i = 2147483646\n");
+  i = 2147483646;
+
+  puts ("t: i++\n");
+  i++;
+
+  puts ("t: i = INT_MIN\n");
+  i = INT_MIN;
+
+  if (strcmp ("-2147483648", itoa (i)))
+    return 34;
+
+  puts ("t: i = -2147483647\n");
+  i = -2147483647;
+
+  puts ("t: i--\n");
+  i--;
+
+
   return 0;
 }
diff --git a/src/math.c b/src/math.c
index b17d0ffe..2a90f933 100644
--- a/src/math.c
+++ b/src/math.c
@@ -33,7 +33,11 @@ assert_number (char const* name, SCM x)
 SCM
 greater_p (SCM x) ///((name . ">") (arity . n))
 {
-  int n = INT_MAX;
+  if (x == cell_nil)
+    return cell_t;
+  assert_number ("greater_p", CAR (x));
+  int n = VALUE (CAR (x));
+  x = CDR (x);
   while (x != cell_nil)
     {
       assert_number ("greater_p", CAR (x));
@@ -48,7 +52,11 @@ greater_p (SCM x) ///((name . ">") (arity . n))
 SCM
 less_p (SCM x) ///((name . "<") (arity . n))
 {
-  int n = INT_MIN;
+  if (x == cell_nil)
+    return cell_t;
+  assert_number ("less_p", CAR (x));
+  int n = VALUE (CAR (x));
+  x = CDR (x);
   while (x != cell_nil)
     {
       assert_number ("less_p", CAR (x));
@@ -81,8 +89,7 @@ SCM
 minus (SCM x) ///((name . "-") (arity . n))
 {
   assert_number ("minus", CAR (x));
-  SCM a = CAR (x);
-  int n = VALUE (a);
+  int n = VALUE (CAR (x));
   x = cdr (x);
   if (x == cell_nil)
     n = -n;
diff --git a/tests/math.test b/tests/math.test
index d9164355..45b496e1 100755
--- a/tests/math.test
+++ b/tests/math.test
@@ -29,54 +29,60 @@ exit $?
 (mes-use-module (srfi srfi-0))
 (mes-use-module (mes test))
 
-(pass-if "+" (seq? (+ 1 2 3) 6))
-(pass-if "*" (seq? (* 3 3 3) 27))
-(pass-if "/" (seq? (/ 9 3) 3))
-(pass-if "remainder" (seq? (remainder 11 3) 2))
-(pass-if "modulo" (seq? (modulo 11 3) 2))
-(pass-if "expt" (seq? (expt 2 3) 8))
-(pass-if "logior" (seq? (logior 0 1 2 4) 7))
+(pass-if-equal "+" 6 (+ 1 2 3))
+(pass-if-equal "*" 27 (* 3 3 3))
+(pass-if-equal "/" 3 (/ 9 3))
+(pass-if-equal "remainder" 2 (remainder 11 3))
+(pass-if-equal "modulo" 2 (modulo 11 3))
+(pass-if-equal "expt" 8 (expt 2 3))
+(pass-if-equal "logior" 7 (logior 0 1 2 4))
 (pass-if-equal "ash"
     8 (ash 1 3))
 (pass-if-equal "ash -1"
     5 (ash 10 -1))
 
-(pass-if "=" (seq? 3 '3))
+(pass-if-equal "=" 3 '3)
 (pass-if "= 2" (not (= 3 '4)))
 
-(pass-if "=" (seq? (=) #t))
-(pass-if "= 1" (seq? (= 0) #t))
-(pass-if "= 2" (seq? (= 0 0) #t))
-(pass-if "= 3" (seq? (= 0 0) #t))
-(pass-if "= 4" (seq? (= 0 1 0) #f))
+(pass-if "=" (=))
+(pass-if "= 1" (= 0))
+(pass-if "= 2" (= 0 0))
+(pass-if "= 3" (= 0 0))
+(pass-if-not "= 4" (= 0 1 0))
 
-(pass-if "<" (seq? (<) #t))
-(pass-if "< 1" (seq? (< 0) #t))
-(pass-if "< 2" (seq? (< 0 1) #t))
-(pass-if "< 3" (seq? (< 1 0) #f))
-(pass-if "< 4" (seq? (< 0 1 2) #t))
-(pass-if "< 5" (seq? (< 0 2 1) #f))
+(pass-if "<" (<))
+(pass-if "< 1" (< 0))
+(pass-if "< 2" (< 0 1))
+(pass-if-not "< 3" (< 1 0))
+(pass-if "< 4" (< 0 1 2))
+(pass-if-not "< 5" (< 0 2 1))
+(pass-if "< INT-MIN" (< -2147483648))
+(pass-if "< INT-MIN" (< -2147483648 0))
+(pass-if "< INT-MAX" (< 2147483647))
 
-(pass-if ">" (seq? (>) #t))
-(pass-if "> 1" (seq? (> 0) #t))
-(pass-if "> 2" (seq? (> 1 0) #t))
-(pass-if "> 3" (seq? (> 0 1) #f))
-(pass-if "> 4" (seq? (> 2 1 0) #t))
-(pass-if "> 5" (seq? (> 1 2 0) #f))
+(pass-if ">" (>))
+(pass-if "> 1" (> 0))
+(pass-if "> 2" (> 1 0))
+(pass-if-not "> 3" (> 0 1))
+(pass-if "> 4" (> 2 1 0))
+(pass-if-not "> 5" (> 1 2 0))
+(pass-if "> INT-MAX" (> 2147483647))
+(pass-if "> INT-MAX 0" (> 2147483647 0))
+(pass-if "> INT-MIN" (> -2147483648))
 
-(pass-if ">=" (seq? (>= 3 2 1) #t))
-(pass-if ">= 2" (seq? (>= 1 2 3) #f))
+(pass-if ">=" (>= 3 2 1))
+(pass-if-not ">= 2" (>= 1 2 3))
 
-(pass-if "<=" (seq? (<= 3 2 1) #f))
-(pass-if "<= 2" (seq? (<= 1 2 3) #t))
+(pass-if-not "<=" (<= 3 2 1))
+(pass-if "<= 2" (<= 1 2 3))
 
-(pass-if "max" (seq? (max 0) 0))
-(pass-if "max 1" (seq? (max 0 1) 1))
-(pass-if "max 2" (seq? (max 1 0 2) 2))
+(pass-if-equal "max" 0 (max 0))
+(pass-if-equal "max 1" 1 (max 0 1))
+(pass-if-equal "max 2" 2 (max 1 0 2))
 
-(pass-if "min" (seq? (min 0) 0))
-(pass-if "min 1" (seq? (min 0 1) 0))
-(pass-if "min 2" (seq? (min 1 0 2) 0))
+(pass-if-equal "min" 0 (min 0))
+(pass-if-equal "min 1" 0 (min 0 1))
+(pass-if-equal "min 2" 0 (min 1 0 2))
 
 (pass-if-equal "#x-10" -16 #x-10)
 
diff --git a/tests/srfi-13.test b/tests/srfi-13.test
index 18c8ff5c..3c7ef853 100755
--- a/tests/srfi-13.test
+++ b/tests/srfi-13.test
@@ -47,6 +47,14 @@ exit $?
                3
                (string-index "foo:bar" #\:))
 
+(pass-if-equal "string->number" 42 (string->number "42"))
+(pass-if-equal "string->number INT-MAX" 2147483647 (string->number "2147483647"))
+(pass-if-equal "string->number INT-MIN" -2147483648 (string->number "-2147483648"))
+(pass-if-equal "number->string" "16" (number->string 16))
+(pass-if-equal "number->string INT-MAX" "2147483647" (number->string 2147483647))
+(pass-if-equal "number->string INT-MIN" "-2147483648" (number->string -2147483648))
+(pass-if-equal "number->string" "-4" (number->string -4))
+
 (pass-if-equal "string-fold"
     "oof"
   (list->string (string-fold cons '() "foo")))