iKnowthat.com has online multimedia educational games for kids in grades PreK through 6 (ages 2-12).

Leon's Math Activity

Kids go on adventures with Super Math Agent, Leon the Chameleon, and solve arithmetic problems along the way! Math topics in this game include counting, skip counting, one-digit addition, two-digit addition, one-digit subtraction, two-digit subtraction, multiplication, two-digit by one-digit multiplication, and division. The problem sets are aligned with mathematics standards and benchmarks for kindergarten, 1st grade, 2nd grade, 3rd grade, 4th grade, 5th grade, and 6th grade.

This game helps kids develop fluency in counting, adding, subtracting, multiplying and dividing whole numbers.  Kids also learn arithmetic facts. Integrated help through the Math Practice activity is also available.  In Math Practice, kids can model problems with counters.

Kids get certificates showing the math problems they solved.  These certificates can be shown to family and friends through email invitations.