diff --git a/1-ProceduralProgramming/3-Types.ipynb b/1-ProceduralProgramming/3-Types.ipynb
index 323c8776e306e4b04ada2e428ad1c1893fbc44ec..9d1b8d9f42aab18fec05dab2657b61bd1dce9efc 100644
--- a/1-ProceduralProgramming/3-Types.ipynb
+++ b/1-ProceduralProgramming/3-Types.ipynb
@@ -533,6 +533,64 @@
     "* `reinterpret_cast`, which is a very brutal cast which changes the type into any other type, regardless of the compatibility of the two types considered. It is a dangerous one that should be considered only in very last resort (usually when interacting with a C library)."
    ]
   },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "### Be wary of mathematical operators and types\n",
+    "\n",
+    "It was already covered in the Hands-On but please bear in mind that this operation: `2/3` is an integer division, so the result will be an `int`, and might not be what you want.\n"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {
+    "vscode": {
+     "languageId": "cpp"
+    }
+   },
+   "outputs": [],
+   "source": [
+    "{\n",
+    "    double a = 2 / 3;\n",
+    "    std::cout << a << std::endl;    // a == 0\n",
+    "}"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "If you really want a `float` division, you have to cast at least one of the value:"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {
+    "vscode": {
+     "languageId": "cpp"
+    }
+   },
+   "outputs": [],
+   "source": [
+    "{\n",
+    "  double a = static_cast<float>(2) / 3;\n",
+    "  std::cout << a << std::endl;\n",
+    "  // this is also valid\n",
+    "  double b = 2. / 3;\n",
+    "  std::cout << b << std::endl;\n",
+    "}"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "Please note that the best would be to explicitly cast both values, to avoid useless implicit conversion."
+   ]
+  },
   {
    "cell_type": "markdown",
    "metadata": {},
@@ -1036,8 +1094,8 @@
    "source": [
     "\n",
     "[© Copyright](../COPYRIGHT.md)   \n",
-    "",
-    "",
+    "\n",
+    "\n",
     "\n"
    ]
   }