diff --git a/lear_year.lua b/001_leap_year.lua
similarity index 81%
rename from lear_year.lua
rename to 001_leap_year.lua
index cc1996a..bb32f3f 100644
--- a/lear_year.lua
+++ b/001_leap_year.lua
@@ -1,5 +1,7 @@
+-- Solution --------------------------------------------------------------------
+
 function leap_year(year)
-   -- Your solution here
+   -- Your implementation here
 end
 
 -- Tests -----------------------------------------------------------------------
diff --git a/resistor_colours.lua b/002_resistor_colours.lua
similarity index 91%
rename from resistor_colours.lua
rename to 002_resistor_colours.lua
index 4a0806d..b74c95d 100644
--- a/resistor_colours.lua
+++ b/002_resistor_colours.lua
@@ -1,3 +1,5 @@
+-- Solution --------------------------------------------------------------------
+
 -- Give the colours whatever values are convenient
 black = undefined
 brown = undefined
@@ -13,7 +15,7 @@ gold = undefined
 silver = undefined
 
 function decode_resistance(colours)
-   -- Your solution here
+   -- Your implementation here
 end
 
 -- Tests -----------------------------------------------------------------------
diff --git a/hamming_distance.lua b/003_hamming_distance.lua
similarity index 79%
rename from hamming_distance.lua
rename to 003_hamming_distance.lua
index 0e4a140..2c74a29 100644
--- a/hamming_distance.lua
+++ b/003_hamming_distance.lua
@@ -1,5 +1,7 @@
+-- Solution --------------------------------------------------------------------
+
 function hamming_distance(str1, str2)
-   -- Your solution here
+   -- Your implementation here
 end
 
 -- Tests -----------------------------------------------------------------------