This year Halloween falls on a school day. Below are resources I have found or have had sent to me by other educators. Please note that these sites aren't compatible with our iPads so if you chose to show them to students in most instances it would have to be as a whole group projected from an LCD (unless you have a laptop cart).
Adjectives with Dracula
A "drag and drop" site that reviews describing with adjectives. Cute sound effects play in the background but can be turned off. This site would be a nice review with 2nd or 3rd grade students.
Halloween Math Facts Practice
This site is flash-based so unfortunately it cannot be used on the iPads. Basic addition on the site would be good for 2nd grade with multiplication and division review available for 4th and 5th grade. http://www.smartygames.com/igre/math/halloweenMath.swf
Great way to have kindergarten or 1st grade students practice beginning sounds!
Have your little ones carve a pumpkin virutally!
The resources listed above were shared by http://www.starrmatica.com/newsletter/oct13.pdf
Halloween by the Numbers
Many of the resources listed above are for younger students. For the older crowd here is a great infographic on Halloween by the numbers. Great for a math talk! The site also contains links to videos around the same theme. http://www.history.com/topics/jack-olantern-history/interactives/halloween-by-the-numbers
Additional Halloween Resources
Halloween Lesson Plans: http://lessonplanspage.com/Halloween.htm/