Math Shark has been a big hit in our home! My 7 year-old son has really enjoyed playing with it and finds it easy to understand. Math Shark has several games to choose from including addition, subtraction, multiplication, division,  decimals, fractions, and percents. Each game also has various skill levels. There is even a calculator mode!  Math Shark is portable and would be a great toy for car trips. It kept my son  entertained for quite some time.