diff --git a/020-returns/020-returns.go b/020-returns/020-returns.go
deleted file mode 100644
index a01a712..0000000
--- a/020-returns/020-returns.go
+++ /dev/null
@@ -1,22 +0,0 @@
-                          // A function can return multiple values.
-
-package main
-
-import "fmt"
-
-func vals() (int, int) {  // The `(int, int)` in this signature shows that the
-    return 3, 7           // function returns 2 ints.
-    
-}
-
-func main() {
-    x, y := vals()        // Use the 2 different return values from the call.
-    fmt.Println(x)
-    fmt.Println(y)
-}
-
-/*
-$ go run 21-returns.go
-3
-7
-*/
diff --git a/020-returns/returns.go b/020-returns/returns.go
new file mode 100644
index 0000000..1325a95
--- /dev/null
+++ b/020-returns/returns.go
@@ -0,0 +1,23 @@
+// ## Multiple Return Values
+
+// In Go, a function can return multiple values.
+// This feature is used often, for example to
+// return a result and an error from a function.
+
+package main
+
+import "fmt"
+
+// The `(int, int)` in this signature shows that the
+// function returns 2 ints.
+func vals() (int, int) {  
+    return 3, 7           
+    
+}
+
+func main() {
+    // Use the 2 different return values from the call.
+    x, y := vals()        
+    fmt.Println(x)
+    fmt.Println(y)
+}
diff --git a/020-returns/returns.sh b/020-returns/returns.sh
new file mode 100644
index 0000000..0a344c6
--- /dev/null
+++ b/020-returns/returns.sh
@@ -0,0 +1,3 @@
+$ go run returns.go
+3
+7
diff --git a/021-varadic/021-varadic.go b/021-varadic/021-varadic.go
deleted file mode 100644
index d6f993e..0000000
--- a/021-varadic/021-varadic.go
+++ /dev/null
@@ -1,27 +0,0 @@
-package main                   // Varadic functions can be called with any number of
-                               // trailing arguments.
-import "fmt"
-
-func add(nums ...int) int {    // Varadic args are declared with `...type` and
-    fmt.Print(nums, " ")       // passed in as a slice.
-    total := 0
-    for _, num := range nums {        
-        total += num                
-    }
-    return total                    
-}                                   
-                                    
-func main() {                       
-    fmt.Println(add(1, 2))     // Varadic functions can be called in the usual way.
-    fmt.Println(add(1, 2, 3))    
-                                    
-    nums := []int{1, 2, 3, 4}  // If you already have multiple args in a slice,
-    fmt.Println(add(nums...))  // apply them to a varadic function using `
-}                              // func(slice...)`.
-
-/*
-$ go run varadic.go
-[1 2] 3
-[1 2 3] 6
-[1 2 3 4] 10
-*/
diff --git a/021-varadic/varadic.go b/021-varadic/varadic.go
new file mode 100644
index 0000000..69fefb7
--- /dev/null
+++ b/021-varadic/varadic.go
@@ -0,0 +1,33 @@
+// ## Varadic Functions
+
+// Varadic functions can be called with any number of
+// trailing arguments. This is useful if you don't know
+// number of arguments that will be needed for a function
+// ahead of time.
+
+package main                   
+                               
+import "fmt"
+
+// Varadic args are declared with `...type` and
+// passed in as a slice.
+func add(nums ...int) int {    
+    fmt.Print(nums, " ")       
+    total := 0
+    for _, num := range nums {        
+        total += num                
+    }
+    return total                    
+}                                   
+                                    
+func main() {
+    // Varadic functions can be called in the usual way.
+    fmt.Println(add(1, 2))     
+    fmt.Println(add(1, 2, 3))    
+
+    // If you already have multiple args in a slice,
+    // apply them to a varadic function using `
+    // func(slice...)`.                              
+    nums := []int{1, 2, 3, 4}  
+    fmt.Println(add(nums...))  
+}                              
diff --git a/021-varadic/varadic.sh b/021-varadic/varadic.sh
new file mode 100644
index 0000000..300c303
--- /dev/null
+++ b/021-varadic/varadic.sh
@@ -0,0 +1,4 @@
+$ go run varadic.go
+[1 2] 3
+[1 2 3] 6
+[1 2 3 4] 10
diff --git a/022-closures/022-closures.go b/022-closures/closures.go
similarity index 94%
rename from 022-closures/022-closures.go
rename to 022-closures/closures.go
index 7de5b73..f034e34 100644
--- a/022-closures/022-closures.go
+++ b/022-closures/closures.go
@@ -1,3 +1,5 @@
+// ## Closures
+
 package main
 
 import "fmt"
diff --git a/023-recursion/023-recursion.go b/023-recursion/recursion.go
similarity index 91%
rename from 023-recursion/023-recursion.go
rename to 023-recursion/recursion.go
index c9cb09c..f55c4d2 100644
--- a/023-recursion/023-recursion.go
+++ b/023-recursion/recursion.go
@@ -1,3 +1,5 @@
+// ## Recursion
+
 package main
 
 import "fmt"
diff --git a/024-defer/024-defer.go b/024-defer/defer.go
similarity index 92%
rename from 024-defer/024-defer.go
rename to 024-defer/defer.go
index d8fa3b8..6a39377 100644
--- a/024-defer/024-defer.go
+++ b/024-defer/defer.go
@@ -1,3 +1,5 @@
+// ## Defer
+
 package main
 
 import "fmt"
diff --git a/025-panic/025-panic.go b/025-panic/025-panic.go
deleted file mode 100644
index 08510af..0000000
--- a/025-panic/025-panic.go
+++ /dev/null
@@ -1,21 +0,0 @@
-                     // Panic
-
-                     // A `panic` means something went unexpectedly wrong.
-                     // Mostly we use it to fail fast on errors that
-                     // shouldn't occur during normal operation.
-package main
-
-func main() {
-	panic("O noes")  // We'll use panic throught this book to check for
-}	                 // unexpected errors. This is the only program in the
-                     // book designed to panic.
-
-/*
-$ go run 26-panic.go
-panic: O noes
-
-goroutine 1 [running]:
-main.main()
-	/.../src/26-panic.go:4 +0x47
-...
-*/
diff --git a/025-panic/panic.go b/025-panic/panic.go
new file mode 100644
index 0000000..6bf9e72
--- /dev/null
+++ b/025-panic/panic.go
@@ -0,0 +1,13 @@
+// ## Panic
+
+// A `panic` means something went unexpectedly wrong.
+// Mostly we use it to fail fast on errors that
+// shouldn't occur during normal operation.
+package main
+
+func main() {
+    // We'll use panic throught this book to check for
+    // unexpected errors. This is the only program in the
+    // book designed to panic.
+	panic("O noes")  
+}	                 
diff --git a/025-panic/panic.sh b/025-panic/panic.sh
new file mode 100644
index 0000000..83dc2ab
--- /dev/null
+++ b/025-panic/panic.sh
@@ -0,0 +1,7 @@
+$ go run 26-panic.go
+panic: O noes
+
+goroutine 1 [running]:
+main.main()
+	/.../src/26-panic.go:4 +0x47
+...
diff --git a/026-recover/026-recover.go b/026-recover/recover.go
similarity index 90%
rename from 026-recover/026-recover.go
rename to 026-recover/recover.go
index d5977be..32094af 100644
--- a/026-recover/026-recover.go
+++ b/026-recover/recover.go
@@ -1,3 +1,5 @@
+// ## Recover
+
 package main
 
 import "fmt"
diff --git a/027-pointers/027-pointers.go b/027-pointers/pointers.go
similarity index 90%
rename from 027-pointers/027-pointers.go
rename to 027-pointers/pointers.go
index 302ec78..cb6fcad 100644
--- a/027-pointers/027-pointers.go
+++ b/027-pointers/pointers.go
@@ -1,3 +1,5 @@
+// ## Pointers
+
 package main
 
 import "fmt"