diff --git a/Notebooks/Chap01/1_1_BackgroundMathematics.ipynb b/Notebooks/Chap01/1_1_BackgroundMathematics.ipynb
index c13cf11..433732d 100644
--- a/Notebooks/Chap01/1_1_BackgroundMathematics.ipynb
+++ b/Notebooks/Chap01/1_1_BackgroundMathematics.ipynb
@@ -171,7 +171,7 @@
         "# Color represents y value (brighter = higher value)\n",
         "# Black = -10 or less, White = +10 or more\n",
         "# 0 = mid orange\n",
-        "# Lines are conoturs where value is equal\n",
+        "# Lines are contours where value is equal\n",
         "draw_2D_function(x1,x2,y)\n",
         "\n",
         "# TODO\n",