Sheppard Software - Lots of fun math grades for grades K-5! The games are not sorted by grade level, so you will need to browse by topic.
Math Playground - Leveled math games for grades K-6. You can click on your grade level and start playing!
Math Game Time - Games, videos, and more for grades PreK-7. You can click on your grade level, or click on what topic you want to practice.
Multiplication.com - Don't let the name fool you, this website has games for many different kinds of math! Choose from addition, subtraction, multiplication, or division games.
Math Play - Lots of cool games to play for grades 1-8. Click on your grade level to find great games!
Math Games - Very fun games! They are not sorted by grade level or topic. Note to parents: this website features ads before games can be played.
PBS Kids - Great tie-ins with PBS Kids shows! These games are not sorted by grade level or topic.
Funbrain - Excellent games! Each game shows which grade level can play.
Free Training Tutorial - Lots of different subjects to choose! Note to parents: this page can be a bit difficult to navigate, with lots of clicks needed and ads to avoid - younger students may require assistance.
Snork's Long Division - Help Snork the monster learn how to do long division!
ThatQuiz - not exactly a game, but still can be very fun! Click here for a quiz which lets you practice measuring with a virtual protractor! (select Measure)