diff --git a/maths/binary_exponentiation.py b/maths/binary_exponentiation.py
index 05de939d1bde..115de127e5e8 100644
--- a/maths/binary_exponentiation.py
+++ b/maths/binary_exponentiation.py
@@ -5,6 +5,45 @@
 
 
 def binary_exponentiation(a: int, n: int) -> int:
+    """
+
+    >>> binary_exponentiation(1, 1)
+    1
+
+    >>> binary_exponentiation(2, 1)
+    2
+
+    >>> binary_exponentiation(3, 1)
+    3
+
+    >>> binary_exponentiation(4, 1)
+    4
+
+    >>> binary_exponentiation(1, 2)
+    1
+
+    >>> binary_exponentiation(2, 2)
+    4
+
+    >>> binary_exponentiation(3, 2)
+    9
+
+    >>> binary_exponentiation(4, 2)
+    16
+
+    >>> binary_exponentiation(1, 3)
+    1
+
+    >>> binary_exponentiation(2, 3)
+    8
+
+    >>> binary_exponentiation(3, 3)
+    27
+
+    >>> binary_exponentiation(4, 3)
+    64
+
+    """
     if n == 0:
         return 1
 
@@ -17,11 +56,6 @@ def binary_exponentiation(a: int, n: int) -> int:
 
 
 if __name__ == "__main__":
-    try:
-        BASE = int(input("Enter Base : ").strip())
-        POWER = int(input("Enter Power : ").strip())
-    except ValueError:
-        print("Invalid literal for integer")
-
-    RESULT = binary_exponentiation(BASE, POWER)
-    print(f"{BASE}^({POWER}) : {RESULT}")
+    import doctest
+
+    doctest.testmod()
diff --git a/maths/binary_exponentiation_3.py b/maths/binary_exponentiation_3.py
index 9cd143e09207..9a99f3af1cf4 100644
--- a/maths/binary_exponentiation_3.py
+++ b/maths/binary_exponentiation_3.py
@@ -12,6 +12,45 @@
 
 
 def b_expo(a: int, b: int) -> int:
+    """
+
+    >>> b_expo(1, 1)
+    1
+
+    >>> b_expo(2, 1)
+    2
+
+    >>> b_expo(3, 1)
+    3
+
+    >>> b_expo(4, 1)
+    4
+
+    >>> b_expo(1, 2)
+    1
+
+    >>> b_expo(2, 2)
+    4
+
+    >>> b_expo(3, 2)
+    9
+
+    >>> b_expo(4, 2)
+    16
+
+    >>> b_expo(1, 3)
+    1
+
+    >>> b_expo(2, 3)
+    8
+
+    >>> b_expo(3, 3)
+    27
+
+    >>> b_expo(4, 3)
+    64
+
+    """
     res = 1
     while b > 0:
         if b & 1:
@@ -24,6 +63,81 @@ def b_expo(a: int, b: int) -> int:
 
 
 def b_expo_mod(a: int, b: int, c: int) -> int:
+    """
+
+    >>> b_expo_mod(1, 1, 7)
+    1
+
+    >>> b_expo_mod(2, 1, 7)
+    2
+
+    >>> b_expo_mod(3, 1, 7)
+    3
+
+    >>> b_expo_mod(4, 1, 7)
+    4
+
+    >>> b_expo_mod(1, 2, 7)
+    1
+
+    >>> b_expo_mod(2, 2, 7)
+    4
+
+    >>> b_expo_mod(3, 2, 7)
+    2
+
+    >>> b_expo_mod(4, 2, 7)
+    2
+
+    >>> b_expo_mod(1, 3, 7)
+    1
+
+    >>> b_expo_mod(2, 3, 7)
+    1
+
+    >>> b_expo_mod(3, 3, 7)
+    6
+
+    >>> b_expo_mod(4, 3, 7)
+    1
+
+    >>> b_expo_mod(1, 1, 5)
+    1
+
+    >>> b_expo_mod(2, 1, 5)
+    2
+
+    >>> b_expo_mod(3, 1, 5)
+    3
+
+    >>> b_expo_mod(4, 1, 5)
+    4
+
+    >>> b_expo_mod(1, 2, 5)
+    1
+
+    >>> b_expo_mod(2, 2, 5)
+    4
+
+    >>> b_expo_mod(3, 2, 5)
+    4
+
+    >>> b_expo_mod(4, 2, 5)
+    1
+
+    >>> b_expo_mod(1, 3, 5)
+    1
+
+    >>> b_expo_mod(2, 3, 5)
+    3
+
+    >>> b_expo_mod(3, 3, 5)
+    2
+
+    >>> b_expo_mod(4, 3, 5)
+    4
+
+    """
     res = 1
     while b > 0:
         if b & 1:
@@ -48,3 +162,9 @@ def b_expo_mod(a: int, b: int, c: int) -> int:
 * the fact : (a*b) % c = ((a%c) * (b%c)) % c
 * Now apply RULE 1 OR 2 whichever is required.
 """
+
+
+if __name__ == "__main__":
+    import doctest
+
+    doctest.testmod()
diff --git a/maths/carmichael_number.py b/maths/carmichael_number.py
index c9c144759246..fdfcd8d77242 100644
--- a/maths/carmichael_number.py
+++ b/maths/carmichael_number.py
@@ -21,6 +21,17 @@ def gcd(a: int, b: int) -> int:
 
 
 def power(x: int, y: int, mod: int) -> int:
+    """
+    >>> power(1,2,3)
+    1
+
+
+    >>> power(2,4,7)
+    2
+
+    >>> power(4,2,9)
+    7
+    """
     if y == 0:
         return 1
     temp = power(x, y // 2, mod) % mod
@@ -31,6 +42,37 @@ def power(x: int, y: int, mod: int) -> int:
 
 
 def is_carmichael_number(n: int) -> bool:
+    """
+    >>> is_carmichael_number(1)
+    True
+
+    >>> is_carmichael_number(2)
+    True
+
+    >>> is_carmichael_number(8)
+    False
+
+    >>> is_carmichael_number(245)
+    False
+
+    >>> is_carmichael_number(561)
+    True
+
+    >>> is_carmichael_number(1105)
+    True
+
+    >>> is_carmichael_number(1729)
+    True
+
+    >>> is_carmichael_number(1728)
+    False
+
+    >>> is_carmichael_number(8910)
+    False
+
+    >>> is_carmichael_number(8911)
+    True
+    """
     b = 2
     while b < n:
         if gcd(b, n) == 1 and power(b, n - 1, n) != 1:
@@ -40,8 +82,6 @@ def is_carmichael_number(n: int) -> bool:
 
 
 if __name__ == "__main__":
-    number = int(input("Enter number: ").strip())
-    if is_carmichael_number(number):
-        print(f"{number} is a Carmichael Number.")
-    else:
-        print(f"{number} is not a Carmichael Number.")
+    import doctest
+
+    doctest.testmod()