diff --git a/module2/exo1/toy_notebook_en.ipynb b/module2/exo1/toy_notebook_en.ipynb
index 64d83b5e7f333bd1fc0f9c684701aa93c634d8e6..258ce502d607edeefbfceb66dd4b742ee799319c 100644
--- a/module2/exo1/toy_notebook_en.ipynb
+++ b/module2/exo1/toy_notebook_en.ipynb
@@ -11,13 +11,7 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "## Asking the maths library"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
+    "## Asking the maths library\n",
     "My computer tells me that $\\pi$ is *approximatively*"
    ]
   },
@@ -43,13 +37,7 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "## Buffon’s needle"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
+    "## Buffon’s needle\n",
     "Applying the method of [Buffon’s needle](https://en.wikipedia.org/wiki/Buffon's_needle_problem), we get the **approximation**"
    ]
   },
@@ -82,13 +70,7 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "## Using a surface fraction argument"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
+    "## Using a surface fraction argument\n",
     "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:"
    ]
   },