Math in the summer? No, you haven't lost your marbles.

It’s time for those lazy days of summer, when our kids just want to swim, eat ice cream, and make sand castles. . .and not spend one moment thinking about math facts. But, when there are a couple of apps that sneak math practice into a really fun—and sometimes tricky—game, we don’t think anyone will be complaining about doing math in July.

{keep reading to see how you can get one of these apps for free today for a limited time!}

The premise of Marble Math, and its younger sibling Marble Math Jr., is pretty simple: Just answer a math question by rolling or dragging a marble through a series of colorful mazes to collect the right answers. But, be careful! There are obstacles in the way like slippery banana peels, sticky goo, and even a hole that “flushes away” some of your points.

Rolling the marble—something I find really fun on an iPad—-or dragging it carefully away from the “wrong” answers, is great fine-motor-skills work, even for some grown ups who think their motor skills are pretty good. For children who have trouble maneuvering the marble, turn “off” the optional obstacles to help insure their success a bit more. Pre-readers can even play by tapping the math question to hear it read out loud.

I’m impressed with the variety of math facts tested in each level, but also by how much customization you can do for your child. In both apps, there are three levels of difficulty that your child can work through. Within each level, a parent can deselect areas that your child has not covered yet in school. Or, you can focus only on those areas that give them trouble, and skip the stuff they know in and out.

Both apps are single-player mode which doesn’t seem to bother my three kids who just like collecting new marbles for getting correct answers. And I like not having to record my scores since, wow, it’s been a long time since I’ve encountered some of these questions. –Christina

Both Marble Math, for kids 9-12+, and Marble Math Jr., for kids 5-8, have been created by Artgig for the iPad, iPhone or iPod Touch.

TODAY ONLY! Marble Math Jr is free on Friday, June 22nd!