Thousands of teachers have discovered the value of classroom blogging, both as an avenue for their communications, but also as a tool for giving voice to what their students are learning and how they are learning.
Class Blogmeister is one of several blogging engines that have been developed specifically for classroom use. You are welcome to explore the writings of teachers and students alike.
National Library of Virtual Manipulative provides opportunities for students to practice their math skills by using manipulative. The topics in that website are appropriate for grades 3-5 and can be used as a center activities.