Here is another robot kit designed to teach your kids technology and coding. The mBot Ranger robot kit can be used to build a robot tank, three-wheel racing car, and self-balancing car. In tank mode, it can move on a variety of terrain. You can easily turn it into Dashing Raptor, which is a three-wheel racing car that runs/spins fast.
The robot has a mainboard based on Arduino Mega 2560. You can enhance your robot thanks to its 10 expansion ports. You also get a graphical programming interface based on Scratch 2.0 for coding. More info is available here.