1.      https://www.khanacademy.org/     Khan Academy is a non-profit educational organization created in 2006 by educator Salman Khan to provide "a free, world-class education for anyone, anywhere". The organization produces micro lectures in the form of YouTube videos.   Khan Academy offers practice exercises, instructional videos, and a personalized learning dashboard that empower learners to study at their own pace in and outside of the classroom.  Their website includes instruction in math, science, computer programming, history, art history, economics, and more.  Their math missions guide learners from kindergarten to calculus using state-of-the-art, adaptive technology that identifies strengths and learning gaps.  
    2.      https://www.matific.com/us/en-us    Matific takes a unique approach to teaching K to 6 math using hands-on and interactive mini-games, called episodes. These immersive bite-sized apps for tablets and personal computers are based on a modular and progressive spiral learning system.
    3.      https://learnzillion.com/     LearnZillion:   This site offers a free and growing set of Math and English Language resources for grades 2-12 that have been developed by expert teachers directly from the Common Core State Standards.  See visual, conceptual explanations of the Common Core State Standards with 4000+ videos tailored for grades 2-12.
    4.      http://nlvm.usu.edu/en/nav/grade_g_1.html      Virtual Manipulatives:  Every math manipulative that you can imagine can be found in virtual form on this website. For example, this site allows students to subtract with base ten blocks, and the blocks that are "taken away" truly go away. In addition to base ten blocks, there are also number lines, clocks, money, tangrams, pattern blocks and more. 
    1.      http://resources.oswego.org/games/       Oswego Math Games:  Some great math games come from this website.  It was designed by teachers for students.  Some favorites are Mathematician (for math facts) and Find the Dog's Bone (for working on 100's chart).
    2.      http://pbskids.org/cyberchase/math-games/       PBS Kids - Cyberchase:  Although there are many great shows on PBS Kids, Cyberchase focuses in on many different math and problem solving concepts.  At the PBS website, there are games and video clips that will help students with math concepts and problem solving.
    3.      http://www.mathplayground.com/       Math Playground:  This site has tons and tons of really great games with tons of different math concepts.  In addition, there are video tutorials that walk kids through many different math concepts.  A favorite feature is the interactive word problems.  Students can do a series of word problems, and the site will keep track of their right and wrong answers.
    4.      http://www2.stetson.edu/~efriedma/puzzle.html       Erich's Puzzle Place:  Critical thinking and solving puzzles are such helpful skills in math.  This site has almost every puzzle imaginable, from Sudoku, to arithmetic puzzles, to rebus puzzles to mazes.
    5.      https://www.eduplace.com/kids/mw/       Math-a-Rama:  This site is more than just games, it also includes manipulatives, brain teasers, an e-glossary, and a place to work on a data survey.  Supported by Houghton Mifflin, this website is sorted by grade level, and is a wonderful resource.
    6.   http://www.ictgames.com/resources.html       ICTGames:  This great site has tons of math games that are nicely aligned to the standards.  The games are sorted by math concepts, and utilize techniques like number lines and abacuses.  
    7.   http://www.tvokids.com/       TVOKids:  The math and science games on this site are wonderful for working on many different math concepts, including counting coins, addition, and telling time.  There are also great videos that demonstrate various math concepts (click on Watch to view videos.
    8. Numberock- A youTube channel that has a variety of videos reviewing math concepts from counting to multiplication.  This channel also features videos in Spanish as well.  Check it Out!