diff --git a/content/01. Introducing notebooks and the RoboLab environment/01.2 Exploring the notebook environment.ipynb b/content/01. Introducing notebooks and the RoboLab environment/01.2 Exploring the notebook environment.ipynb
index 3d51cbed..74d75e40 100644
--- a/content/01. Introducing notebooks and the RoboLab environment/01.2 Exploring the notebook environment.ipynb	
+++ b/content/01. Introducing notebooks and the RoboLab environment/01.2 Exploring the notebook environment.ipynb	
@@ -98,7 +98,7 @@
     "\n",
     "I have also noted that my Microsoft Outlook and Slack clients emphasise text if I wrap it in `*` marks. The Slack client also styles text wrapped using backticks (`` ` ``) in a monospace, code style font.\n",
     "\n",
-    "As well as generating headings by prefixing a line with one or more `#` signs, markdown also supports level 1 heading generation by placing one or more `=` characters on the line underneath the heading text and level 2 headings by using one or more `-` characters. Underling a heading with one or two lines is a common technique when creating handwritten or simple text documents."
+    "As well as generating headings by prefixing a line with one or more `#` signs, markdown also supports level 1 heading generation by placing one or more `=` characters on the line underneath the heading text and level 2 headings by using two or more `-` characters. Underling a heading with one or two lines is a common technique when creating handwritten or simple text documents."
    ]
   },
   {
@@ -107,12 +107,16 @@
     "hidden": true
    },
    "source": [
-    "heading\n",
+    "Level 1 heading\n",
     "=\n",
     "\n",
-    "## heading\n",
+    "## Level 2 heading\n",
     "\n",
-    "heading\n",
+    "\n",
+    "Level 2 heading\n",
+    "--\n",
+    "\n",
+    "Level 1 heading\n",
     "==="
    ]
   },
@@ -539,7 +543,7 @@
     "\n",
     "As well as using the provided notebooks, you are also encouraged to create and save your own notebooks containing your own code experiments. You should also feel free to use the simulator to try out your own self-created challenges and to satisfy your own curiosity about whether you can get the simulated robot to perform tasks of your own devising as well as the suggested activity tasks.\n",
     "\n",
-    "One thing you might want to do is create your on summary cell at the end of each notebook to record your own summary notes about what you learned working through the notebook. Remember, you can create your own cells and then colour them using the appropriate toolbar button."
+    "One thing you might want to do is create your own summary cell at the end of each notebook to record your own summary notes about what you learned working through the notebook. Remember, you can create your own cells and then colour them using the appropriate toolbar button."
    ]
   },
   {