diff --git a/module2/exo1/toy_notebook_en.ipynb b/module2/exo1/toy_notebook_en.ipynb
index f71d803cf4d570311cbf18e98cd5b24877d37da8..c1692e6dfdcc26b97071ed602e4a18866c33f299 100644
--- a/module2/exo1/toy_notebook_en.ipynb
+++ b/module2/exo1/toy_notebook_en.ipynb
@@ -25,7 +25,13 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    " **1.1 Asking the maths library**\n",
+    " **1.1 Asking the maths library**"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
     " My computer tells me that $\\pi$ is *approximatively*"
    ]
   },
@@ -51,7 +57,13 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "**1.2 Buffon's needle**\n",
+    "**1.2 Buffon's needle**"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
     "Applying the method of [Buffon's needle](https://en.wikipedia.org/wiki/Buffon%27s_needle_problem), we get the __approximation__"
    ]
   },
@@ -84,7 +96,13 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "**1.3 Using a surface fraction argument**\n",
+    "**1.3 Using a surface fraction argument**"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
     "A method that is easier to understand and does not make use of the $\\sin$ function is based on the fact that if $X\\sim U(0,1)$ and $Y\\sim U(0,1)$, then $P[X^2+Y^2\\leq 1] = \\pi/4$ (see [\"Monte Carlo method\" on Wikipedia](https://en.wikipedia.org/wiki/Monte_Carlo_method)). The following code uses this approach:"
    ]
   },