diff --git a/CHANGELOG.md b/CHANGELOG.md
index 61ee1d8..d6dc151 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,13 @@
 # Changelog
 
+## [Unreleased]
+
+### Added
+
+- Added `divide(a, b)` function in `functions.py` to perform division.
+- Added `multiply(a, b)` function in `functions.py` to perform multiplication.
+
+
 ## [1.0.0] - 2025-05-11
 
 ### Added
diff --git a/functions.py b/functions.py
index d33c9bb..89202a7 100644
--- a/functions.py
+++ b/functions.py
@@ -4,4 +4,12 @@ def add(a, b):
 
 def minus(a, b):
     """Subtract b from a."""
-    return a - b
\ No newline at end of file
+    return a - b
+
+def divide(a, b):
+    """Divide a by b."""
+    return a / b
+
+def multiply(a, b):
+    """Multiply two numbers"""
+    return a * b 
diff --git a/tests/test_cases.json b/tests/test_cases.json
new file mode 100644
index 0000000..eeed81b
--- /dev/null
+++ b/tests/test_cases.json
@@ -0,0 +1,12 @@
+[
+    {"input": {"a": 2, "b": 3}, "expected": 6},
+    {"input": {"a": -1, "b": 5}, "expected": -5},
+    {"input": {"a": 0, "b": 100}, "expected": 0},
+    {"input": {"a": 7, "b": -3}, "expected": -21},
+    {"input": {"a": -4, "b": -2}, "expected": 8},
+    {"input": {"a": 1, "b": 0}, "expected": 0},
+    {"input": {"a": 123, "b": 456}, "expected": 56088},
+    {"input": {"a": 10, "b": 10}, "expected": 100},
+    {"input": {"a": 0, "b": 0}, "expected": 0},
+    {"input": {"a": 999, "b": -1}, "expected": 999}
+]
\ No newline at end of file
diff --git a/tests/test_cases_divide.json b/tests/test_cases_divide.json
new file mode 100644
index 0000000..1064607
--- /dev/null
+++ b/tests/test_cases_divide.json
@@ -0,0 +1,12 @@
+[
+    {"input": {"a": 10, "b": 2}, "expected": 5},
+    {"input": {"a": -10, "b": 2}, "expected": -5},
+    {"input": {"a": 0, "b": 1}, "expected": 0},
+    {"input": {"a": 10, "b": -2}, "expected": -5},
+    {"input": {"a": 1, "b": 3}, "expected": 0.3333333333333333},
+    {"input": {"a": 100, "b": 10}, "expected": 10},
+    {"input": {"a": -100, "b": -10}, "expected": 10},
+    {"input": {"a": 7, "b": 7}, "expected": 1},
+    {"input": {"a": 0, "b": 10}, "expected": 0},
+    {"input": {"a": 10, "b": 0}, "expected_error": "ZeroDivisionError"}
+]
\ No newline at end of file
diff --git a/tests/test_code_divide.py b/tests/test_code_divide.py
new file mode 100644
index 0000000..9c5214b
--- /dev/null
+++ b/tests/test_code_divide.py
@@ -0,0 +1,25 @@
+import unittest
+import json
+from functions import divide
+
+class TestDivideFunction(unittest.TestCase):
+    def setUp(self):
+        # JSON 파일에서 테스트 케이스 로드
+        with open("tests/test_cases_divide.json", "r") as f:
+            self.test_cases = json.load(f)
+
+    def test_divide(self):
+        for case in self.test_cases:
+            a = case["input"]["a"]
+            b = case["input"]["b"]
+
+            if "expected" in case:
+                with self.subTest(a=a, b=b):
+                    self.assertAlmostEqual(divide(a, b), case["expected"], places=7)
+            elif "expected_error" in case:
+                with self.subTest(a=a, b=b):
+                    with self.assertRaises(eval(case["expected_error"])):
+                        divide(a, b)
+
+if __name__ == "__main__":
+    unittest.main()
\ No newline at end of file
diff --git a/tests/test_multiply.py b/tests/test_multiply.py
new file mode 100644
index 0000000..672aea9
--- /dev/null
+++ b/tests/test_multiply.py
@@ -0,0 +1,18 @@
+import json
+import unittest
+from functions import multiply
+
+class TestMultiplyFunction(unittest.TestCase):
+    def test_multiply_cases(self):
+        with open("tests/test_cases.json", "r") as f:
+            test_cases = json.load(f)
+
+        for case in test_cases:
+            a = case["input"]["a"]
+            b = case["input"]["b"]
+            expected = case["expected"]
+            with self.subTest(a=a, b=b, expected=expected):
+                self.assertEqual(multiply(a, b), expected)
+
+if __name__ == "__main__":
+    unittest.main()
\ No newline at end of file