diff --git a/printNumbers/functions/square.py b/printNumbers/functions/square.py
new file mode 100644
index 0000000..acdcf1e
--- /dev/null
+++ b/printNumbers/functions/square.py
@@ -0,0 +1,28 @@
+# -*- coding: utf-8 -*-
+#
+# square.py
+#
+# This file is part of printNumbers.
+#
+# Copyright (C) 2022 P. Carlsson, IEK-8, FZ Juelich
+#
+# printNumbers is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 2 of the License, or
+# (at your option) any later version.
+#
+# printNumbers is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with printNumbers.  If not, see <http://www.gnu.org/licenses/>.
+
+def Square(n):
+    '''
+    :param n:   Operand
+    :return:    n*n
+    '''
+    
+    return (n*n)
diff --git a/printNumbers/parameters.py b/printNumbers/parameters.py
index aebe0c3..54a7b8b 100755
--- a/printNumbers/parameters.py
+++ b/printNumbers/parameters.py
@@ -29,6 +29,7 @@
 CONST_MAX_OPERAND_VAL = 20
 CONST_FUNC_CODE_FIBONACCI = 0
 CONST_FUNC_CODE_FACTORIAL = 1
+CONST_FUNC_CODE_SQUARE = 2
 
 class Parameters(object):
 
@@ -43,6 +44,8 @@ def __setParameters(self, cmdLineArgs):
             self.functionIndex = CONST_FUNC_CODE_FIBONACCI
         elif cmdLineArgs['--factorial']:
             self.functionIndex = CONST_FUNC_CODE_FACTORIAL
+        elif cmdLineArgs['--square']:
+            self.functionIndex = CONST_FUNC_CODE_SQUARE
 
     @property
     def operand(self):
diff --git a/printNumbers/printNumbers.py b/printNumbers/printNumbers.py
index 9f9ef0e..18cfe1b 100755
--- a/printNumbers/printNumbers.py
+++ b/printNumbers/printNumbers.py
@@ -1,3 +1,4 @@
+#! /bin/env python
 # -*- coding: utf-8 -*-
 #
 # printNumbers.py
@@ -27,24 +28,28 @@
 """
 Usage:
   printNumbers.py -h --help
-  printNumbers.py [--fibonacci|--factorial] <operand>
+  printNumbers.py [--fibonacci|--factorial|--square] <operand>
 
 Options:
   -h --help       Print usage.
   --fibonacci     Print the fibonacci sequence.
   --factorial     Print the factorial.
+  --square        Print the square of the operand.
 """
 
 from docopt import docopt
 from parameters import *
 from functions.fibonacci import *
 from functions.factorial import *
+from functions.square import *
+
 
 #
 # FUNCTION TABLE
 #
 functionTable = { CONST_FUNC_CODE_FIBONACCI : FibonacciSequence,
                   CONST_FUNC_CODE_FACTORIAL : Factorial,
+                  CONST_FUNC_CODE_SQUARE : Square,
                 }
 
 #
@@ -67,3 +72,5 @@
         print('fib(' + str(params.operand) + ') =', result)
     elif params.functionIndex == CONST_FUNC_CODE_FACTORIAL:
         print(str(params.operand) + '! =', str(result))
+    elif params.functionIndex == CONST_FUNC_CODE_SQUARE:
+        print(str(params.operand) + ' squared is ', str(result))
diff --git a/printNumbers/unittests/runTestSuite.py b/printNumbers/unittests/runTestSuite.py
index f3dca23..c375a8b 100755
--- a/printNumbers/unittests/runTestSuite.py
+++ b/printNumbers/unittests/runTestSuite.py
@@ -27,6 +27,7 @@
 
 import test_factorial
 import test_fibonacci
+import test_square
 
 
 def suite():
@@ -34,6 +35,7 @@ def suite():
 
     suite.addTest(test_factorial.suite())
     suite.addTest(test_fibonacci.suite())
+    suite.addTest(test_square.suite())
 
     return suite
 
diff --git a/printNumbers/unittests/test_square.py b/printNumbers/unittests/test_square.py
new file mode 100644
index 0000000..b1b4c88
--- /dev/null
+++ b/printNumbers/unittests/test_square.py
@@ -0,0 +1,56 @@
+# -*- coding: utf-8 -*-
+#
+# test_square.py
+#
+# This file is part of PrintNumbers.
+#
+# Copyright (C) 2022 P. Carlsson, IEK8, FZ Juelich
+#
+# PrintNumbers is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 2 of the License, or
+# (at your option) any later version.
+#
+# PrintNumbers is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with PrintNumbers.  If not, see <http://www.gnu.org/licenses/>.
+
+#
+# Unit tests: 'square'.
+#
+
+import sys, os
+sys.path.append(os.path.join(os.path.dirname(__file__), '..'))
+
+import unittest
+from functions.square import *
+
+class TestSquare(unittest.TestCase):
+
+    def test_value_0(self):
+        self.assertEqual(Square(0), 0)
+
+    def test_value_1(self):
+        self.assertEqual(Square(1), 1)
+
+    def test_value_2(self):
+        self.assertEqual(Square(2), 4)
+
+    def test_value_20(self):
+        self.assertEqual(Square(20), 400)
+
+
+def suite():
+    suite = unittest.makeSuite(TestSquare, 'test')
+    return suite
+
+def run():
+    runner = unittest.TextTestRunner(verbosity = 2)
+    runner.run(suite())
+
+if __name__ == "__main__":
+    run()