All right, kids! Raise your hand if you like algebra! Hmmm. Now, raise your hands if you like Angry Birds! I see. What if I were to tell you that Angry Birds had been surpassed in the App Store — by a game that involves solving algebra equations? Because that's what DragonBox did.

Do I have your attention now?

Well, okay, I should clarify: when DragonBox pre-launched in Norway, where it was developed, it shot up the charts and became the #1 most purchased app in Norway. I honestly don't know how many Norwegians play Angry Birds (though apparently it's still a lot). But that doesn't make DragonBox's accomplishment anything to scoff at. More importantly, the app works.

Within a couple hours, most kids playing DragonBox will be able to start solving simple algebraic equations, and what's more, they'll be having fun and they may not even know they're learning algebra at first. Also surprising is that they don't even need to know basic arithmetic to play the game. I showed DragonBox to my five-year-old and she loved it, and didn't even want me to play ahead because she wanted to be the one to unlock all the levels.

So, how does a relatively unknown company from Norway make algebra so fun and easy to learn that my kids fight over who gets to play it? Read on and I'll tell you.

[DragonBox is available for $2.99 for iOS and Android devices, and there's also a Mac version. DragonBox+ includes 100 additional equations for extra practice for $5.99: iOS, Android, Mac.]

First, a bit about how DragonBox actually works.

There are five "worlds," each with twenty levels, and as you progress through the levels the "dragons" hatch and grow into their full-sized versions. While this in itself has nothing to do with algebra, I mention this because my kids love this. It's a very tiny incentive (along with earning stars) but they really want to beat the next level to watch the dragon grow into its next form. I was told that the dragons were all drawn by a fourteen-year-old girl, and they're a lot of fun. (They aren't all typical dragons — One starts off more like a fish, one looks like a squid, and so on.)

You are presented with a big screen with two trays, each containing a number of "cards" with different images on it. Somewhere on the screen there will be a little box with a star on it, sparkling and glowing. The app gives very minimal instructions in a hand-written font with arrows pointing to relevant spots on the screen, but it tells you to get the box by itself. At first you do this simply by tapping the green spirally cards, which vanish when you tap them. Then, you'll start to get some "night" versions of cards — drag these onto the "day" versions and they become green swirls, which you already know how to handle.

After you've gotten past several levels of moving cards around and tapping on swirls, you'll get a few cards down at the bottom which you can drag onto the trays — but whenever you drag a card onto one side, you have to also drag a copy to the other side as well. (This, of course, simulates adding the same number to both sides.) And then, a few levels on, you learn that you can flip these extra cards from day to night (and vice versa) before dragging them onto the trays.

As the game progresses, you'll start seeing cards that are above and below each other, with a bar in the middle — and you'll learn to cancel these out by dragging one onto the other, which then turns into a one-dot. And you'll learn that a one-dot vanishes when you drag it onto a card it's attached to (with a little grey dot between them). These, of course, are fractions — multiplication and division — but you don't need to know that to play the game, either.

Some other funny things happen, too. Sometimes there's no box, but there is a little white square with an "x" on it, and it's sparkling. So you isolate the "x." Sometimes instead of weird little creatures there are letters on the cards like "c" or "b" and sometimes there are things that look like dice, white squares with some number of dots on them.

Once you get to World 3, the cards are no longer scattered willy-nilly in the two trays, but are arranged in a line, with plus signs between them and an equals sign between the two trays.

And then the cards once again turn into numbers and letters instead of little pictures... and then finally you get something like that screenshot near the top of the post, where the trays have faded out completely and there are just the hint of card outlines, and — voila! — you're solving algebraic equations.

Aside from isolating the box, you're also challenged to complete the level in as few moves as possible, which gets you a an extra star. You also get another star if you have the right number of cards at the end — that is, you've simplified the equation as much as possible.

When I first started playing with DragonBox to see how it worked, I was amazed at how simple it was. I've always been good at math myself and algebra was always one of my favorites. But I know it's something that a lot of students have trouble with — and certainly not something that is usually taught before middle school, sometimes not until high school. It really hadn't occurred to me at all that I could teach beginning algebra to my third-grader, let alone my five-year-old. When I showed it to them and saw how easily they picked it up, I was blown away.

Jean-Baptiste Huynh is a Vietnamese Frenchman living in Norway, who taught math for several years and was frustrated with the way math is taught in schools. He wanted his kids to learn algebra in a way that made sense to them, and with tablets and gamification of education he thought that there must be some way to create an app that would make algebra easier to learn. So he started up a company called We Want to Know, aimed at creating some user-friendly educational games that are (1) really educational and (2) really games. If DragonBox is any indication, he's on the right path so far.

Huynh was visiting the US last week — meeting with gamification visionaries and seeking investors — and we were able to meet over lunch during his very busy travel schedule to talk about DragonBox and education.

DragonBox is making me reconsider all the times I've called an educational app "innovative." Many educational apps are some form of flashcard, a way to enforce rote repetition and memory with some veneer of interactivity and multimedia layered on top. To be honest, I'm pretty tired of interactive picture books — yes, there are definitely some fun ones out there, but they're not really any more "innovative" than pop-up books read out loud by an adult. It's just an extension of the medium.

Here, though, we have an app that is allowing kids to learn a tricky subject through a gradual introduction of new rules and concepts — just like playing through an in-game tutorial where you first learn to look around, then walk, then jump, then pull out your weapons and fire, and then you're off and running and you never had to sit down and read a manual. When the developers tested their app with hundreds of students in Norway, they found that more than 30% of them were able to solve equations after an hour of playing the game, and that rate more than doubled after two hours.

Huynh was tired of hearing that kids couldn't learn algebra, and he was especially frustrated with the countless apps that purport to be educational but are nothing more than flash cards with some bells and whistles. He sees tablet computers as a truly disruptive technology that can change the way we teach and learn. We Want to Know did extensive testing of DragonBox in schools — often with several kids crowded around a single table — and he said he loved watching their "aha" moments when something clicked and they got it.

The downside, though, is that teachers don't know what to do with this. They're invested in the system, textbook publishers are invested in the status quo, and it's hard to flip the classroom. He said in some cases after introducing kids to the app, then he would observe the teachers and they really didn't know how to carry forward the lessons learned from the app. This will present a tricky challenge — what does a middle school algebra teacher do if kindergarteners can start learning to solve equations within a couple of hours? Certainly any good teacher would be thrilled for their students to catch on to something so quickly — but how do you then move from there to real-world applications or a deeper understanding of the principles? Certainly conventional teaching methods will be hard to combine with the app.

(Here's a short clip of my daughters playing through parts of Chapter 4, working with each other on errors.)

One of the things about the app which Huyhn pointed out is that it does let you figure things out on your own. It doesn't give you the answers, but it enforces the rules. If you add a card to one side, it won't let you do anything else until you add the same card to the other side, balancing the equation. Of course, this is something that doesn't happen when you solve equations on paper, so that's where the practice and teacher involvement is important. The app will make sure you're solving its equations — but if you move beyond the app to new problems, you have to remember the rules yourself.

It reminds me of playing board games on the iPad or on a computer: it's not the same as playing in real life, but one of the distinct advantages is that you don't have to remember all the rules yourself. If you can't play a tile in a particular location in Carcassonne, the app simply won't let you put it there. When you try to take a second face-up locomotive card in Ticket to Ride, the app doesn't allow it. Play the app enough times, and the rules gradually become second nature, without having to consult the rulebook or have an experienced player walk you through it.

Of course, the flip side to that in the case of DragonBox is that you don't learn the reasons for the rules. My kids (particularly my five-year-old) have no idea why, when you drag a card below another one, you have to drag it below all the other cards on the screen. They don't know why cards in the numerator and denominator can cancel each other out and become a "1." Now, you show this to an older kid who knows arithmetic and has started studying algebra, and they'll know why these rules are there. For my kids, it's just a matter of learning the rules of this game — and eventually I think that will serve them well — but there's not really any theory behind it. This may be where the teacher's involvement is crucial. It frees them up from checking over each student's work as they solve equations, and allows them to focus on the whys of algebra.

Huyhn said that the company is currently working on other apps as well: simpler concepts like arithmetic and more complex concepts like quadratic equations and functions, and then moving on into other subjects as well. It's hard for me to picture exactly what these apps will look like, but if they're anything like DragonBox then sign me up. For more about We Want to Know, visit the website. (Again, they're currently seeking investors so if you're looking for a promising company, you may want to check it out.)

DragonBox is designed for iPads and Android tablets, but also works well on iPhones and Android phones, and there is also a Mac version.

Disclosure: GeekDad received a review code for the app.