diff --git a/introduction/02_introduction_to_python_2.ipynb b/introduction/02_introduction_to_python_2.ipynb
index 4ea943136d36ca5164fb6b75366ea3c10102ef6c..589da2e4b1d1dcb95eb27dd5995ae58f9feeec56 100644
--- a/introduction/02_introduction_to_python_2.ipynb
+++ b/introduction/02_introduction_to_python_2.ipynb
@@ -566,7 +566,9 @@
   {
    "cell_type": "code",
    "execution_count": 20,
-   "metadata": {},
+   "metadata": {
+    "collapsed": true
+   },
    "outputs": [],
    "source": [
     "l = [1, 2, 3, 4]\n",
@@ -1198,7 +1200,9 @@
   {
    "cell_type": "code",
    "execution_count": 43,
-   "metadata": {},
+   "metadata": {
+    "collapsed": true
+   },
    "outputs": [],
    "source": [
     "if False:\n",
@@ -1237,7 +1241,9 @@
   {
    "cell_type": "code",
    "execution_count": 44,
-   "metadata": {},
+   "metadata": {
+    "collapsed": true
+   },
    "outputs": [],
    "source": [
     "# Add 42 to this list.\n",
@@ -1257,7 +1263,9 @@
   {
    "cell_type": "code",
    "execution_count": 45,
-   "metadata": {},
+   "metadata": {
+    "collapsed": true
+   },
    "outputs": [],
    "source": [
     "while False:\n",
@@ -1319,7 +1327,9 @@
   {
    "cell_type": "code",
    "execution_count": 47,
-   "metadata": {},
+   "metadata": {
+    "collapsed": true
+   },
    "outputs": [],
    "source": [
     "range?"
@@ -1417,7 +1427,9 @@
   {
    "cell_type": "code",
    "execution_count": 51,
-   "metadata": {},
+   "metadata": {
+    "collapsed": true
+   },
    "outputs": [],
    "source": [
     "colors = ['red', 'white', 'blue', 'orange']\n",
@@ -1678,6 +1690,31 @@
     "There are many more useful iterables in Python."
    ]
   },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "<div class=\"alert alert-success\">\n",
+    "<h1>Hands on!</h1>\n",
+    "\n",
+    "<ol>\n",
+    "  <li>Make a list with 10 integer elements. Sum all the items in the list.</li>\n",
+    "  <li>Make a new list from the above one that does not include the 0th, 4th and 5th elements.\n",
+    "  <li>Sum only the elements from the first list which are between the 2nd and 6th elements.\n",
+    "  <li>Make a new list that includes only the elements that are greater than 10 from the first list.\n",
+    "  <li>Food.\n",
+    "    <ul>\n",
+    "      <li>Create a dictionary for food products called \"prices\" and put some values in it, e.g., \"apples\": 2, \"oranges\": 1.5, \"pears\": 3, ...</li>\n",
+    "      <li>Create a corresponding dictionary called \"stocks\" and put the stock values in it, e.g., \"apples\": 0, \"oranges\": 1, \"pears\": 10, ...</li>\n",
+    "      <li>Print stock and price information for each food item.</li>\n",
+    "      <li>Determine and print how much money you would make if you sold all of your food products.\n",
+    "    </ul>\n",
+    "  </li>\n",
+    "</ol>\n",
+    "\n",
+    "</div>"
+   ]
+  },
   {
    "cell_type": "markdown",
    "metadata": {
@@ -1865,21 +1902,21 @@
  "metadata": {
   "celltoolbar": "Slideshow",
   "kernelspec": {
-   "display_name": "Python 2",
+   "display_name": "Python 3",
    "language": "python",
-   "name": "python2"
+   "name": "python3"
   },
   "language_info": {
    "codemirror_mode": {
     "name": "ipython",
-    "version": 2
+    "version": 3
    },
    "file_extension": ".py",
    "mimetype": "text/x-python",
    "name": "python",
    "nbconvert_exporter": "python",
-   "pygments_lexer": "ipython2",
-   "version": "2.7.12"
+   "pygments_lexer": "ipython3",
+   "version": "3.5.2"
   }
  },
  "nbformat": 4,