diff --git a/10_arrays/TODO.md b/10_arrays/TODO.md
new file mode 100644
index 0000000..9902b8f
--- /dev/null
+++ b/10_arrays/TODO.md
@@ -0,0 +1 @@
+Here, a new section on `numpy` Arrays and, maybe, `pandas` DataFrames will be added.
\ No newline at end of file
diff --git a/CONTENTS.md b/CONTENTS.md
index bdad0d7..46e16ce 100644
--- a/CONTENTS.md
+++ b/CONTENTS.md
@@ -262,6 +262,7 @@ If this is not possible,
     - [review questions <img height="12" style="display: inline-block" src="static/link/to_nb.png">](https://nbviewer.jupyter.org/github/webartifex/intro-to-python/blob/develop/09_mappings/07_review.ipynb)
     - [further resources <img height="12" style="display: inline-block" src="static/link/to_nb.png">](https://nbviewer.jupyter.org/github/webartifex/intro-to-python/blob/develop/09_mappings/08_resources.ipynb)
       [<img height="12" style="display: inline-block" src="static/link/to_mb.png">](https://mybinder.org/v2/gh/webartifex/intro-to-python/develop?urlpath=lab/tree/09_mappings/08_resources.ipynb)
+  - *Chapter 10*: Arrays & Dataframes
   - *Chapter 11*: Classes & Instances
     - [content <img height="12" style="display: inline-block" src="static/link/to_nb.png">](https://nbviewer.jupyter.org/github/webartifex/intro-to-python/blob/develop/11_classes/00_content.ipynb)
       [<img height="12" style="display: inline-block" src="static/link/to_mb.png">](https://mybinder.org/v2/gh/webartifex/intro-to-python/develop?urlpath=lab/tree/11_classes/00_content.ipynb)
diff --git a/README.md b/README.md
index 49ae3d0..f3fffd8 100644
--- a/README.md
+++ b/README.md
@@ -22,6 +22,7 @@ For a more *detailed version* with **clickable links**
   - *Chapter 7*: Sequential Data
   - *Chapter 8*: Map, Filter, & Reduce
   - *Chapter 9*: Mappings & Sets
+  - *Chapter 10*: Arrays & Dataframes
   - *Chapter 11*: Classes & Instances