diff --git a/pythonintro/Classes.ipynb b/pythonintro/Classes.ipynb
index 6500478008b3a84c0caaadade2459b1837b6259a..dcd8647c71f0fb46694dfd4b69d885bf2db55b87 100644
--- a/pythonintro/Classes.ipynb
+++ b/pythonintro/Classes.ipynb
@@ -42,7 +42,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 1,
+   "execution_count": 2,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -69,7 +69,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 2,
+   "execution_count": 3,
    "metadata": {},
    "outputs": [
     {
@@ -362,7 +362,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.10.6"
+   "version": "3.10.12"
   },
   "orig_nbformat": 4,
   "vscode": {
diff --git a/pythonintro/Classes_Inheritance.ipynb b/pythonintro/Classes_Inheritance.ipynb
index f7d0a9cd8768530e8fed133c5e45313cfff4f4c3..502a5326d87e06c5354a0f568a34fbd41f4ec886 100644
--- a/pythonintro/Classes_Inheritance.ipynb
+++ b/pythonintro/Classes_Inheritance.ipynb
@@ -150,7 +150,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.10.6"
+   "version": "3.10.12"
   },
   "orig_nbformat": 4,
   "vscode": {
diff --git a/pythonintro/Classes_PrivateVariables.ipynb b/pythonintro/Classes_PrivateVariables.ipynb
index ef6439def102bbb76d66b37d2f81aa0f6967aba2..68dcc4ee9407afdb7a7a7d5bad312efdef0bda59 100644
--- a/pythonintro/Classes_PrivateVariables.ipynb
+++ b/pythonintro/Classes_PrivateVariables.ipynb
@@ -169,7 +169,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.10.6"
+   "version": "3.10.12"
   },
   "orig_nbformat": 4,
   "vscode": {
diff --git a/pythonintro/Functions.ipynb b/pythonintro/Functions.ipynb
index 85deb0a4404aa8a0a37186d02936990db77faac6..b3a0df79775dc0ded6f21557692713274a21437e 100644
--- a/pythonintro/Functions.ipynb
+++ b/pythonintro/Functions.ipynb
@@ -84,23 +84,25 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 3,
+   "execution_count": 10,
    "metadata": {},
    "outputs": [
     {
      "name": "stdout",
      "output_type": "stream",
      "text": [
-      "The sum is: 7.1\n"
+      "<class 'int'> <class 'int'>\n",
+      "The sum is: 7 3 4\n"
      ]
     }
    ],
    "source": [
     "def my_sum(x, y):\n",
-    "    return x + y\n",
+    "    print(type(x), type(y))\n",
+    "    return x +y, x, y \n",
     "\n",
-    "sum = my_sum(3,4)\n",
-    "print('The sum is: {}'.format(sum))"
+    "sum, a ,b  = my_sum(3,4)\n",
+    "print('The sum is: {} {} {}'.format(sum,a,b))"
    ]
   },
   {
@@ -505,13 +507,16 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 2,
+   "execution_count": 11,
    "metadata": {},
    "outputs": [
     {
      "name": "stdout",
      "output_type": "stream",
      "text": [
+      "the Fibonacci number is: -3\n",
+      "the Fibonacci number is: -2\n",
+      "the Fibonacci number is: -1\n",
       "the Fibonacci number is: 0\n",
       "the Fibonacci number is: 1\n",
       "the Fibonacci number is: 1\n",
@@ -528,7 +533,7 @@
    "source": [
     "Fibonacci = lambda n:  n if n <= 1 else Fibonacci(n-1) + Fibonacci(n-2)\n",
     "\n",
-    "for i in range(0,10):\n",
+    "for i in range(-3,10):\n",
     "    fib = Fibonacci(i)\n",
     "    print('the Fibonacci number is: {}'.format(fib))\n"
    ]
@@ -550,7 +555,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.10.6"
+   "version": "3.10.12"
   },
   "orig_nbformat": 4,
   "vscode": {
diff --git a/pythonintro/solutions/Solution_AccountClass.ipynb b/pythonintro/solutions/Solution_AccountClass.ipynb
index 2849ad16455865d10214f0d3e8bdc7071b962d70..47fe7ea94a7204694fe854aca1723c3dd2059807 100644
--- a/pythonintro/solutions/Solution_AccountClass.ipynb
+++ b/pythonintro/solutions/Solution_AccountClass.ipynb
@@ -42,6 +42,7 @@
     "class Account():\n",
     "    def __init__(self, name, balance = 0):\n",
     "        self._name = name\n",
+    "        # what can we improve in the following line?\n",
     "        self._balance = int(balance)\n",
     "        if self._balance < 0:\n",
     "            self._balance = 0\n",