PBS Kids
In this website, students can play educational games in all subject areas, including language arts, reading, math, social studies, and science. They can play games, like Curious George, Cat in the Hat, and more. My favorites are Magic Cake Maker, Big Bird's Letters, Can You Fill It, Feed Gnochi, Weather Wheel, Light It Right, and Snowflake Match.
ABCya
ABCya.com is the leader in free educational kids computer games and activities for elementary students to learn on the web. All children's educational computer activities were created or approved by certified school teachers. All educational games are free and are modeled from primary grade lessons and enhanced to provide an interactive way for children to learn.
Grade level lessons incorporate areas such as math and language arts while introducing basic computer skills. Many of the kindergarten and first grade activities are equipped with sound to enhance understanding. Fun children's Holiday activities are available in grade level sections!
http://www.abcya.com/
Starfall
Interactive early reading stories and printables. This site is very colorful and loads really fast. Excellent resource!
Free Math Worksheets
Free math worksheets for elementary school and home use. This includes generators for math drills, flashcards, time, money, and more!
http://www.mathfactcafe.com/
NCWiseOwl
Virtual Math Manipulatives
Online math tools that students can use to help with math homework.