In the game Shape Surveyer you never know what you'll find if you dig geometry. You will be shown a rectangle with the dimensions labeled and must calculate the area or perimeter of the rectangle. For each problem you get correct, you will receive a piece of an archeological puzzle. The game is over when you get all the puzzle pieces.
From the pull down menus in orange (Math Games and Arcade - Algebra), you can select linear equations to solve (addition, subtraction, multiplication, and division). If you don't like the timer, you can click on the Practice Mode (on the left) to slow things down. Try out the 2-step equations too!