diff --git a/Chapter10 - Intro to Convolutional Neural Networks - Learning Edges and Corners.ipynb b/Chapter10 - Intro to Convolutional Neural Networks - Learning Edges and Corners.ipynb
index ab04fc5..347f615 100644
--- a/Chapter10 - Intro to Convolutional Neural Networks - Learning Edges and Corners.ipynb	
+++ b/Chapter10 - Intro to Convolutional Neural Networks - Learning Edges and Corners.ipynb	
@@ -363,8 +363,8 @@
     "kernel_cols = 3\n",
     "num_kernels = 16\n",
     "\n",
-    "hidden_size = ((input_rows - kernel_rows) * \n",
-    "               (input_cols - kernel_cols)) * num_kernels\n",
+    "hidden_size = ((input_rows - kernel_rows +1) * \n",
+    "               (input_cols - kernel_cols +1)) * num_kernels\n",
     "\n",
     "# weights_0_1 = 0.02*np.random.random((pixels_per_image,hidden_size))-0.01\n",
     "kernels = 0.02*np.random.random((kernel_rows*kernel_cols,\n",