diff --git a/module2/exo1/toy_notebook_en.ipynb b/module2/exo1/toy_notebook_en.ipynb
index 7580ee9eda8a930a9101ceccbf8a0dec598007ac..022d9b9df199c913251df375831f2d77aa219f37 100644
--- a/module2/exo1/toy_notebook_en.ipynb
+++ b/module2/exo1/toy_notebook_en.ipynb
@@ -70,7 +70,7 @@
     "## 1.3 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\n",
-    "fact that if *X ∼ U(0, 1)* and *Y ∼ U(0, 1)* then P[X<sup>2</sup> + Y<sup>2</sup> ≤ 1] = &#960;/4 (see [\"Monte Carlo method\"\n",
+    "fact that if *X ∼ U(0, 1)* and *Y ∼ U(0, 1)* then P[X² + Y² ≤ 1] = &#960;/4 (see [\"Monte Carlo method\"\n",
     "on Wikipedia](https://en.wikipedia.org/wiki/Monte_Carlo_method)). The following code uses this approach:"
    ]
   },
@@ -115,7 +115,7 @@
    "outputs": [],
    "source": [
     "It is then straightforward to obtain a (not really good) approximation to π by counting how\n",
-    "many times, on average, X<sup>2</sup> + Y<sup>2</sup> is smaller than 1:"
+    "many times, on average, X² + Y² is smaller than 1:"
    ]
   },
   {