diff --git a/module2/exo1/toy_notebook_en.ipynb b/module2/exo1/toy_notebook_en.ipynb
index 6ba03f75705096624e1429089cdcfcae476db3e3..52474811c702e7729c2c8e9095274a73f0d3d3fc 100644
--- a/module2/exo1/toy_notebook_en.ipynb
+++ b/module2/exo1/toy_notebook_en.ipynb
@@ -4,8 +4,8 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "# 1. On the computation of $\\pi$\n",
-    "## 1.1 Asking the maths library\n",
+    "# On the computation of $\\pi$\n",
+    "## Asking the maths library\n",
     "My computer tells me that 𝜋 is approximativey"
    ]
   },
@@ -33,7 +33,7 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "## 1.2 Buffon’s needle"
+    "## Buffon’s needle"
    ]
   },
   {
@@ -72,7 +72,7 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "## 1.3 Using a surface fraction argument\n",
+    "## Using a surface fraction argument\n",
     "\n",
     "A method that is easier to understand and does not make use of the sin function is based on the fact that if $X ∼ U(0, 1)$ and $Y ∼ U(0, 1)$, then $P[X^2 + Y^2 ≤ 1] = \\pi/4$ (see [\"Monte Carlo method\" on Wikipedia)](https://en.wikipedia.org/wiki/Monte_Carlo_method). The following code uses this approach:\n"
    ]