diff --git a/ladderz/src/pre_algebra/unit1.rs b/ladderz/src/pre_algebra.rs
similarity index 100%
rename from ladderz/src/pre_algebra/unit1.rs
rename to ladderz/src/pre_algebra.rs
diff --git a/ladderz/src/pre_algebra/mod.rs b/ladderz/src/pre_algebra/mod.rs
deleted file mode 100644
index c042765..0000000
--- a/ladderz/src/pre_algebra/mod.rs
+++ /dev/null
@@ -1,5 +0,0 @@
-/// Factors and multiples
-mod unit1;
-
-#[doc(inline)]
-pub use unit1::*;
diff --git a/notebooks/pre-algebra/unit1.ipynb b/notebooks/pre-algebra.ipynb
similarity index 99%
rename from notebooks/pre-algebra/unit1.ipynb
rename to notebooks/pre-algebra.ipynb
index 4ff66a8..95ff413 100644
--- a/notebooks/pre-algebra/unit1.ipynb
+++ b/notebooks/pre-algebra.ipynb
@@ -9,13 +9,6 @@
     "</a>"
    ]
   },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "# Unit 1: Factors and multiples"
-   ]
-  },
   {
    "cell_type": "markdown",
    "metadata": {},