One website for fun and free math games for kids is FunBrain.com. As of 2015, the site offers over 20 math related games.
Players can create free accounts and track their game play at FunBrain.com. The site also offers games to help children with reading skills.
Another site for math games is CoolMath4Kids.com. Games are available for fractions, division, addition, subtraction and multiplication, among many other areas of math. Flash cards and brain bender games are also available.
PrimaryGames.com is an additional site for math games. Games and activities are available by grade level.