diff --git a/test13.py b/test13.py
index 5c49a40..b45b271 100644
--- a/test13.py
+++ b/test13.py
@@ -1,4 +1,4 @@
-from test12 import BoundedInt
+from BoundedInt import BoundedInt
 
 class BoundedIntTester:
     def __init__(self):
@@ -11,6 +11,9 @@ class BoundedIntTester:
             print(f"❌ Test 1 failed, int(bi1) = {int(bi1)}, expected 0xdeadbeef")
 
     def test2(self):
+        """
+        Test that addition works for two BoundedInts, and throws an error if the bounds are exceeded.
+        """
         bi2 = BoundedInt(1, min = 0, max = 1)
         bi3 = BoundedInt(1, min = 0, max = 1)
         try:
@@ -20,6 +23,9 @@ class BoundedIntTester:
             print(f"✅ Test 2 passed!")
 
     def test3(self):
+        """
+        Test that addition works for two BoundedInts, and throws an error if the bounds are exceeded.
+        """
         bi4 = BoundedInt(1, min = 0, max = 1)
         bi5 = BoundedInt(2, min = 0, max = 1)
         try:
@@ -28,7 +34,33 @@ class BoundedIntTester:
         except ValueError as err:
             print(f"✅ Test 3 passed!")
 
+    def test4(self):
+        """
+        Test that addition works for a BoundedInt and a regular int, and throws an error if the bounds are exceeded.
+        """
+        bi7 = BoundedInt(1, min = 0, max = 1)
+        bi8 = 2
+        try:
+            bi9 = bi7 + bi8
+            print(f"❌ Test 4 failed!")
+        except ValueError as err:
+            print(f"✅ Test 4 passed!")
+
+    def test5(self):
+        """
+        Test that subtraction works for a BoundedInt and a regular int, and throws an error if the bounds are exceeded.
+        """
+        bi10 = BoundedInt(1, min = 0, max = 1)
+        bi11 = 2
+        try:
+            bi12 = bi10 - 11
+            print(f"❌ Test 5 failed!")
+        except ValueError as err:
+            print(f"✅ Test 5 passed!")
+
 tester = BoundedIntTester()
 tester.test1()
 tester.test2()
-tester.test3()
\ No newline at end of file
+tester.test3()
+tester.test4()
+tester.test5()
\ No newline at end of file