diff --git a/s23/Gurmail_lecture_notes/04_Vars_and_Exprs/.ipynb_checkpoints/lec_04_Vars_and_Exprs-checkpoint.ipynb b/s23/Gurmail_lecture_notes/04_Vars_and_Exprs/.ipynb_checkpoints/lec_04_Vars_and_Exprs-checkpoint.ipynb
index b82e110a37b3ca43db008c367aa9d880817d0427..e4dab02aa86392c930b055417974382ac7421303 100644
--- a/s23/Gurmail_lecture_notes/04_Vars_and_Exprs/.ipynb_checkpoints/lec_04_Vars_and_Exprs-checkpoint.ipynb
+++ b/s23/Gurmail_lecture_notes/04_Vars_and_Exprs/.ipynb_checkpoints/lec_04_Vars_and_Exprs-checkpoint.ipynb
@@ -19,7 +19,7 @@
     "* shift + enter = cell execution (= Run)\n",
     "* ESC + A = add a cell above the current cell\n",
     "* ESC + B = add a cell below the current cell\n",
-    "* ESc + L = toggle the line number"
+    "* ESc + L = toggle the line numbers"
    ]
   },
   {
diff --git a/s23/Gurmail_lecture_notes/04_Vars_and_Exprs/.ipynb_checkpoints/lec_04_Vars_and_Exprs_template_Gurmail_lec1-checkpoint.ipynb b/s23/Gurmail_lecture_notes/04_Vars_and_Exprs/.ipynb_checkpoints/lec_04_Vars_and_Exprs_template_Gurmail_lec1-checkpoint.ipynb
index e7fdb3a2739efdcbd41fccb04b71286369eca793..ce7668bfb4872bd6164998cc368bb8fe082654ba 100644
--- a/s23/Gurmail_lecture_notes/04_Vars_and_Exprs/.ipynb_checkpoints/lec_04_Vars_and_Exprs_template_Gurmail_lec1-checkpoint.ipynb
+++ b/s23/Gurmail_lecture_notes/04_Vars_and_Exprs/.ipynb_checkpoints/lec_04_Vars_and_Exprs_template_Gurmail_lec1-checkpoint.ipynb
@@ -19,7 +19,7 @@
     "* shift + enter = cell execution (= Run)\n",
     "* ESC + A = add a cell above the current cell\n",
     "* ESC + B = add a cell below the current cell\n",
-    "* ESc + L = toggle the line number"
+    "* ESc + L = toggle the line numbers"
    ]
   },
   {
diff --git a/s23/Gurmail_lecture_notes/04_Vars_and_Exprs/.ipynb_checkpoints/lec_04_Vars_and_Exprs_template_Gurmail_lec2-checkpoint.ipynb b/s23/Gurmail_lecture_notes/04_Vars_and_Exprs/.ipynb_checkpoints/lec_04_Vars_and_Exprs_template_Gurmail_lec2-checkpoint.ipynb
index e7fdb3a2739efdcbd41fccb04b71286369eca793..ce7668bfb4872bd6164998cc368bb8fe082654ba 100644
--- a/s23/Gurmail_lecture_notes/04_Vars_and_Exprs/.ipynb_checkpoints/lec_04_Vars_and_Exprs_template_Gurmail_lec2-checkpoint.ipynb
+++ b/s23/Gurmail_lecture_notes/04_Vars_and_Exprs/.ipynb_checkpoints/lec_04_Vars_and_Exprs_template_Gurmail_lec2-checkpoint.ipynb
@@ -19,7 +19,7 @@
     "* shift + enter = cell execution (= Run)\n",
     "* ESC + A = add a cell above the current cell\n",
     "* ESC + B = add a cell below the current cell\n",
-    "* ESc + L = toggle the line number"
+    "* ESc + L = toggle the line numbers"
    ]
   },
   {
diff --git a/s23/Gurmail_lecture_notes/04_Vars_and_Exprs/lec_04_Vars_and_Exprs.ipynb b/s23/Gurmail_lecture_notes/04_Vars_and_Exprs/lec_04_Vars_and_Exprs.ipynb
index b82e110a37b3ca43db008c367aa9d880817d0427..e4dab02aa86392c930b055417974382ac7421303 100644
--- a/s23/Gurmail_lecture_notes/04_Vars_and_Exprs/lec_04_Vars_and_Exprs.ipynb
+++ b/s23/Gurmail_lecture_notes/04_Vars_and_Exprs/lec_04_Vars_and_Exprs.ipynb
@@ -19,7 +19,7 @@
     "* shift + enter = cell execution (= Run)\n",
     "* ESC + A = add a cell above the current cell\n",
     "* ESC + B = add a cell below the current cell\n",
-    "* ESc + L = toggle the line number"
+    "* ESc + L = toggle the line numbers"
    ]
   },
   {
diff --git a/s23/Gurmail_lecture_notes/04_Vars_and_Exprs/lec_04_Vars_and_Exprs_template_Gurmail_lec1.ipynb b/s23/Gurmail_lecture_notes/04_Vars_and_Exprs/lec_04_Vars_and_Exprs_template_Gurmail_lec1.ipynb
index e7fdb3a2739efdcbd41fccb04b71286369eca793..ce7668bfb4872bd6164998cc368bb8fe082654ba 100644
--- a/s23/Gurmail_lecture_notes/04_Vars_and_Exprs/lec_04_Vars_and_Exprs_template_Gurmail_lec1.ipynb
+++ b/s23/Gurmail_lecture_notes/04_Vars_and_Exprs/lec_04_Vars_and_Exprs_template_Gurmail_lec1.ipynb
@@ -19,7 +19,7 @@
     "* shift + enter = cell execution (= Run)\n",
     "* ESC + A = add a cell above the current cell\n",
     "* ESC + B = add a cell below the current cell\n",
-    "* ESc + L = toggle the line number"
+    "* ESc + L = toggle the line numbers"
    ]
   },
   {
diff --git a/s23/Gurmail_lecture_notes/04_Vars_and_Exprs/lec_04_Vars_and_Exprs_template_Gurmail_lec2.ipynb b/s23/Gurmail_lecture_notes/04_Vars_and_Exprs/lec_04_Vars_and_Exprs_template_Gurmail_lec2.ipynb
index e7fdb3a2739efdcbd41fccb04b71286369eca793..ce7668bfb4872bd6164998cc368bb8fe082654ba 100644
--- a/s23/Gurmail_lecture_notes/04_Vars_and_Exprs/lec_04_Vars_and_Exprs_template_Gurmail_lec2.ipynb
+++ b/s23/Gurmail_lecture_notes/04_Vars_and_Exprs/lec_04_Vars_and_Exprs_template_Gurmail_lec2.ipynb
@@ -19,7 +19,7 @@
     "* shift + enter = cell execution (= Run)\n",
     "* ESC + A = add a cell above the current cell\n",
     "* ESC + B = add a cell below the current cell\n",
-    "* ESc + L = toggle the line number"
+    "* ESc + L = toggle the line numbers"
    ]
   },
   {