diff --git a/index.html b/index.html
index 708c782..715f65b 100644
--- a/index.html
+++ b/index.html
@@ -78,6 +78,7 @@ By <a target=_blank href="mailto:inexorabletash@gmail.com">Joshua Bell</a>
     <option value="sample.columns">&nbsp; Columns (Arthur Allen)</option>
     <option value="sample.tetris">&nbsp; Tetris (Arthur Allen)</option>
     <option value="sample.dicegame">&nbsp; Colorful Dice (Gregory Lewis)</option>
+    <option value="sample.aritm">&nbsp; Aritm - Mental calculation (Mikael O. Bonnier)</option>
     <option value="sample.unfinishedmaze">&nbsp; Unfinished Maze (Alexander G. Tozzi)</option>
     <option value="sample.dragonsmaze">&nbsp; Dragon's Maze (Russell Hokanson)</option>
     <option value="sample.blackhole">&nbsp; Black Hole Maze (S.M.Compton c/o Melody Ayres-Griffiths)</option>