Looking for math puzzles that will expand your students' problem-solving abilities — and entertain them in the process? You've come to the right place! Check out these interactive riddles and games for fun with your whole class — both on- and off-line.

Start your Web tour at A+ Math's Game Room. Here you'll find math games that will help your students practice their addition, subtraction, multiplication, and division skills — while they try to solve puzzles like concentration, matho (think bingo, only with math), and the hidden picture. These games provide challenges for kids at all different levels of math learning.

Next stop, Funbrain.com! This site offers two great ways for kids to practice math skills. For all the baseball lovers out there, there's Math Baseball — in which kids score hits and runs by finding the correct solution to math problems. Kids can choose which kind of skill they want to practice (addition, subtraction, multiplication, and division) and what level they want to play at (easy, medium, hard, and super brain).

And with Funbrain's Change Maker, kids can practice their real-world math skills by figuring out how much of each kind of change (pennies, nickels, dimes, etc.) they should get back for a given purchase. This game is tougher than you think, so be prepared to stump your students! Fortunately, like Math Baseball, there are levels of difficulty for kids to choose from.

And for a quick challenge you can do offline with your class, check out Houghton Mifflin's Brain Teasers. These word problems are leveled for grades 3-4, 5-6, and 7 and up, and there's a new one every week. Make sure to come back every Thursday to see the new challenge for the week — and to check the solution to the previous week's challenge.

For something a bit more abstract, check out the Most Colorful Math of All, where kids are challenged to color in maps without having the same color touch on any borders. But what does this have to do with math? The answer to that question is provided, as are extension activities and key concepts.