When I did my student teaching, my mentor teacher gave me a copy of this poem that helps students memorize the rules. I thought some of you upper grade teachers might want to have a copy to hang in your classroom and to print off for students.
(Click on the picture for a download.)
I make a copy on card stock for students to put in the back of their homework binder, I include a multiplication chart so that they always have one at home to help them with their homework. Click here for that download.
Also, I attended an awesome workshop once that gave me some great ideas of lessons to teach divisibility. You can find the lessons here in the Core Academy Teacher Handbook from 2007.
(Click the picture to view the handbook. You can find the lessons starting on page 4-17.)
P.S. On end of the level testing my students always score super high in rules of divisibility. As much as I would like to attribute that to me and my awesome teaching stills (hehe!), I'm sure it has to do with students memorizing the poem.