diff --git a/module2/exo1/toy_notebook_en.ipynb b/module2/exo1/toy_notebook_en.ipynb
index be233dec6a997026da9a716edcf34262d9aac1e8..e1c831a6092a4bb13fd2d0db901a2080486191aa 100644
--- a/module2/exo1/toy_notebook_en.ipynb
+++ b/module2/exo1/toy_notebook_en.ipynb
@@ -11,13 +11,7 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "### 1.1. Asking the maths library"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
+    "### 1.1. Asking the maths library\n",
     "My computer tells me that $\\pi$ is *approximatively*"
    ]
   },
@@ -43,13 +37,7 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "### 1.2 Buffon’s needle"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
+    "### 1.2 Buffon’s needle\n",
     "Applying the method of [Buffon’s needle](https://en.wikipedia.org/wiki/Buffon%27s_needle_problem), we get the **approximation**"
    ]
   },
@@ -82,13 +70,7 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "### 1.3 Using a surface fraction argument"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
+    "### 1.3 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 $X \\approx U(0, 1)$ and $Y \\approx U(0, 1)$, then $P[X^2 + Y^2 $\\le$ 1] = \\pi/4$ (see [\"Monte Carlo method\" on Wikipedia](https://en.wikipedia.org/wiki/Monte_Carlo_method)). The following code uses this approach:"
    ]
   },