diff --git a/Chapter1_Introduction/Ch1_Introduction_PyMC2.ipynb b/Chapter1_Introduction/Ch1_Introduction_PyMC2.ipynb
index 26b7b71a..50b51fbb 100644
--- a/Chapter1_Introduction/Ch1_Introduction_PyMC2.ipynb
+++ b/Chapter1_Introduction/Ch1_Introduction_PyMC2.ipynb
@@ -205,7 +205,7 @@
     "\n",
     "# For the already prepared, I'm using Binomial's conj. prior.\n",
     "for k, N in enumerate(n_trials):\n",
-    "    sx = plt.subplot(len(n_trials) / 2, 2, k + 1)\n",
+    "    sx = plt.subplot(len(n_trials) // 2, 2, k + 1)\n",
     "    plt.xlabel(\"$p$, probability of heads\") \\\n",
     "        if k in [0, len(n_trials) - 1] else None\n",
     "    plt.setp(sx.get_yticklabels(), visible=False)\n",
diff --git a/Chapter1_Introduction/Ch1_Introduction_PyMC3.ipynb b/Chapter1_Introduction/Ch1_Introduction_PyMC3.ipynb
index be24102a..f13a04fd 100644
--- a/Chapter1_Introduction/Ch1_Introduction_PyMC3.ipynb
+++ b/Chapter1_Introduction/Ch1_Introduction_PyMC3.ipynb
@@ -209,7 +209,7 @@
     "\n",
     "# For the already prepared, I'm using Binomial's conj. prior.\n",
     "for k, N in enumerate(n_trials):\n",
-    "    sx = plt.subplot(len(n_trials)/2, 2, k+1)\n",
+    "    sx = plt.subplot(len(n_trials)//2, 2, k+1)\n",
     "    plt.xlabel(\"$p$, probability of heads\") \\\n",
     "        if k in [0, len(n_trials)-1] else None\n",
     "    plt.setp(sx.get_yticklabels(), visible=False)\n",
diff --git a/Chapter1_Introduction/Ch1_Introduction_Pyro.ipynb b/Chapter1_Introduction/Ch1_Introduction_Pyro.ipynb
index 32366073..6ee1c268 100644
--- a/Chapter1_Introduction/Ch1_Introduction_Pyro.ipynb
+++ b/Chapter1_Introduction/Ch1_Introduction_Pyro.ipynb
@@ -166,7 +166,7 @@
     "\n",
     "# For the already prepared, I'm using Binomial's conj. prior.\n",
     "for k, N in enumerate(n_trials):\n",
-    "    sx = plt.subplot(len(n_trials)/2, 2, k+1)\n",
+    "    sx = plt.subplot(len(n_trials)//2, 2, k+1)\n",
     "    plt.xlabel(\"$p$, probability of heads\") \\\n",
     "        if k in [0, len(n_trials)-1] else None\n",
     "    plt.setp(sx.get_yticklabels(), visible=False)\n",
diff --git a/Chapter1_Introduction/Ch1_Introduction_TFP.ipynb b/Chapter1_Introduction/Ch1_Introduction_TFP.ipynb
index 117da5e1..96cf0f1a 100644
--- a/Chapter1_Introduction/Ch1_Introduction_TFP.ipynb
+++ b/Chapter1_Introduction/Ch1_Introduction_TFP.ipynb
@@ -437,7 +437,7 @@
         "# For the already prepared, I'm using Binomial's conj. prior.\n",
         "plt.figure(figsize(16, 9))\n",
         "for i in range(len(num_trials)):\n",
-        "    sx = plt.subplot(len(num_trials)/2, 2, i+1)\n",
+        "    sx = plt.subplot(len(num_trials)//2, 2, i+1)\n",
         "    plt.xlabel(\"$p$, probability of heads\") \\\n",
         "    if i in [0, len(num_trials)-1] else None\n",
         "    plt.setp(sx.get_yticklabels(), visible=False)\n",
@@ -1435,4 +1435,4 @@
       ]
     }
   ]
-}
\ No newline at end of file
+}