diff --git a/primality/primality.py b/primality/primality.py
index a738922..95a936f 100644
--- a/primality/primality.py
+++ b/primality/primality.py
@@ -210,3 +210,64 @@ def rand_prime(m: int, n: int, strategy: RandomStrategy = RandomStrategy.RANDOM_
         return secrets.SystemRandom().choice(found_primes)
     else:
         raise ValueError("Couldn't find the selected strategy")
+
+def next_prime_after_operation(n : int, m : int, operation : str):
+    """
+    Arguments:
+        {n} integer -- The Starting index of Range
+        {m} integer -- The Ending index of Range
+        {string} string -- The operation to be performed
+
+    Returns:
+        integer -- The next prime number after the sum of the operation
+    """
+    if not isinstance(n, int):
+        raise TypeError("next_prime_after_sum() expect parameter n to be int. Given: "
+                        + str(type(n)) + '.')
+    if not isinstance(m, int):
+        raise TypeError("next_prime_after_sum() expect parameter m to be int. Given: "
+                        + str(type(m)) + '.')
+    if not isinstance(operation, str):
+        raise TypeError("next_prime_after_sum() expect parameter string to be string. Given: "
+                        + str(type(operation)) + '.')
+    if operation == "+":
+        return next_prime(n + m)
+    elif operation == "-":
+        return next_prime(n - m)
+    elif operation == "*":
+        return next_prime(n * m)
+    elif operation == "/":
+        return next_prime(int(n / m))
+    else:
+        raise ValueError("Couldn't find the selected operation")
+
+
+def prev_prime_before_operation(n : int, m : int, operation : str):
+    """
+    Arguments:
+        {n} integer -- The Starting index of Range
+        {m} integer -- The Ending index of Range
+        {string} string -- The operation to be performed
+
+    Returns:
+        integer -- The previous prime number before the operation
+    """
+    if not isinstance(n, int):
+        raise TypeError("prev_prime_before_op() expect parameter n to be int. Given: "
+                        + str(type(n)) + '.')
+    if not isinstance(m, int):
+        raise TypeError("prev_prime_before_op() expect parameter m to be int. Given: "
+                        + str(type(m)) + '.')
+    if not isinstance(operation, str):
+        raise TypeError("prev_prime_before_op() expect parameter string to be string. Given: "
+                        + str(type(operation)) + '.')
+    if operation == "+":
+        return prev_prime(n + m)
+    elif operation == "-":
+        return prev_prime(n - m)
+    elif operation == "*":
+        return prev_prime(n * m)
+    elif operation == "/":
+        return prev_prime(int(n / m))
+    else:
+        raise ValueError("Couldn't find the selected operation")
\ No newline at end of file
diff --git a/tests/test_primes.py b/tests/test_primes.py
index 200e5ad..a07ecce 100644
--- a/tests/test_primes.py
+++ b/tests/test_primes.py
@@ -65,6 +65,36 @@ def test_rand_primes_random_lib(self):
                 self.assertGreater(random_prime, lower_bound)
                 self.assertLess(random_prime, upper_bound)
 
+    def test_next_prime_after_operation_sum(self):
+        next_prime_after_sum = primality.next_prime_after_operation(10, 20, '+')
+        self.assertEqual(next_prime_after_sum, 31)
 
+    def test_next_prime_after_operation_subtraction(self):
+        next_prime_after_subtraction = primality.next_prime_after_operation(20, 10, '-')
+        self.assertEqual(next_prime_after_subtraction, 11)
+
+    def test_next_prime_after_operation_multiplication(self):
+        next_prime_after_multiplication = primality.next_prime_after_operation(10, 10, '*')
+        self.assertEqual(next_prime_after_multiplication, 101)
+
+    def test_next_prime_after_operation_division(self):
+        next_prime_after_division = primality.next_prime_after_operation(100, 10, '/')
+        self.assertEqual(next_prime_after_division, 11)
+
+    def test_prev_prime_before_operation_sum(self):
+        prev_prime_before_sum = primality.prev_prime_before_operation(10, 20, '+')
+        self.assertEqual(prev_prime_before_sum, 29)
+
+    def test_prev_prime_before_operation_subtraction(self):
+        prev_prime_before_subtraction = primality.prev_prime_before_operation(20, 10, '-')
+        self.assertEqual(prev_prime_before_subtraction, 7)
+
+    def test_prev_prime_before_operation_multiplication(self):
+        prev_prime_before_multiplication = primality.prev_prime_before_operation(10, 10, '*')
+        self.assertEqual(prev_prime_before_multiplication, 97)
+
+    def test_prev_prime_before_operation_division(self):
+        prev_prime_before_division = primality.prev_prime_before_operation(100, 10, '/')
+        self.assertEqual(prev_prime_before_division, 7)
 if __name__ == '__main__':
     unittest.main()