IS AN EASY WAY TO LEARN THE PRESIDENTS OF THE UNITED STATES BY ORDER
Flashcards help most students memorize facts like this.
Practice, practice, practice.
Check these sites for more help.
http://www.washingtonpost.com/wp-dyn/content/article/2009/02/15/AR2009021501546.html
http://www.youtube.com/watch?v=kI1ZR7RzFXU