Get away from that cube, kid, Daddy's got the fever on him. Daddy's looking at his first chance ever to solve not just one but two of the six sides, you hear me? Right.

And the kid, who happens in this case to be the 8-year-old daughter of a Rubik's Cube jockey in Takoma Park, backs off with the kind of startled disappointment usually inspired only by a biting pony.

Rubik's Cube is a grown-up's toy, kid, a puzzle that's moving like fast food right now, more than 9 million sold, according to the Ideal Toy Corp. It is this year's Hoola Hoop or Bongo Board, a hot tub for the mind. When carried in public it has a certain talismanic aspect, like the tiny staffs that Anglican bishops tote. If you've got it with you, it is maybe the only thing in the world that may make you wish that the line in the bank were longer. Esthetically, it's the perfect toy for the Leggo generation: no numbers, no letters, just colors lined up in jolly little squares. Politically, it's just the thing for the Reagan years: It offers indefinite postponement of reward, and it requires that you constantly undo what you've just done in order to move further along to the solution.

Chris Ottaway is barefoot and 17, curled up in an old chair, her hands emitting a terrible slithering grind, which is the mating call of the Rubik's Cube she holds.

The cube is about the size of a squared snowball; making a snowball, in fact, requires hand motions not dissimilar to the motions Chris is going through. The cube comprises 27 little cubes bearing six different colors. Chris rotates them, nine at a time, on both vertical and horizontal axes, to make that peculiar sound, so akin to the grinding of teeth by most people who try to solve this thing.

"I just did zap," she says. Zap is a move invented by her uncle, a mathematician, to transpose the positions of three cubes touching only on their corners so that not only are the cubes in correct position, but have their colors aligned with the center cubes on their respective faces . . . you get the idea.

The idea is to align all the little cubes so that the big cube shows one color on each side, the way it looked in the package when you bought it. This is just one of an estimated 43,252,003,274,489,856,000 color patterns the cube can be manipulated into. The odds, therefore, are pretty slim that you'll get it right by chance. A computer that could count a million patterns a second, for instance, would take 1.4 million years to do the job. It will take Chris Ottaway, a junior at T.C. Williams High School who plans to major in math in college, and who would like to become an astronaut, about 2 1/2 minutes. She has the idea.

The cube was invented in 1974 by a Hungarian design professor named Erno Rubik. It has since become a chronically sold-out item in toy departments, a pet plaything of mathematicians who apply algorithms and group theory to solving it, and possibly the most frustrating puzzle since the famous Sam Loyd "15" game -- the little frame with 15 numbered tiles and 16 spaces -- was said to have driven 1,500 people insane when it was introduced in the 19th century.

It's so frustrating that the Ideal Toy people can sell a solution for $2. Bantam Books has just published one for $1.95. A British mathematician, David Singmaster, has written a treatise titled "Notes on Rubik's Cube." Singmaster guesses that people who solve the puzzle without help require an average of two weeks of concentrated effort. In Scientific American, mathematician Douglas Hofstadter says that "if you are destined to solve the unscrambling problem at all, it will take you somewhere between five hours and a year."

Some theorists hold that it can be done in a mere 20 moves, though the best recorded so far is 50 by a Britisher named Morven B. Thistlethwaite. Chris Ottaway's father, Malcolm, a bearded mathematician sitting at a picnic table in his back yard, says he refuses to take lessons from his daughter or anyone else, refuses to speculate on how long it will take him, estimates only that he's about "one-third of the way along, I think."

In the living room Chris Ottaway studies the cube with benign severity. She keeps twisting it, as if it were a jam jar with six caps. A little gold heart-shaped locket rocks on her chest. She says: "I taught a friend of mine how to solve it, and one day we saw a guy doing it at the pool. My friend went over and said, 'Oh, what's that?' The guy started telling her how to do it. She set up the top for me, then I took it and said: 'What am I supposed to do?' The guy told me and I finished it for him in about 30 seconds."

Cube racing! There are also cube rankings, cube status, cube duels, cubist's thumb, which is the equivalent, here, of tennis elbow, and first reported, according to Scientific American, by cubist Dame Kathleen Oilerenshaw, formerly lord mayor of Manchester.

Brian Hunt, a junior at Blair Montgomery High School in Silver Spring, has been clocked at under 60 seconds.

"You can see the kids crowding around him at lunch time, asking him to solve their cubes," says one of his math teachers, Allan Graham.

"I'd like to meet that guy," says Chris Ottaway.

Playing with it is a little like doing those College Board questions on spatial relations, the ones that ask you to imagine a sheet of paper folded in three, then imagine holes cut in it, then guess what it will look like when unfolded. In other words, the cube can bring on what Meat Loaf, in the movie "Roadie," referred to as "brain lock."

"It's the biggest thing Ideal has ever had, in terms of number of units sold," says a spokesman.

At Games magazine, editor Philip Wiswell says: "I've spent about 500 hours with it. I got so frustrated. I had one friend who's very competitive. His daughter asked him to fix it for her and he was up all night. About 4:30 in the morning he got some solvent, unglued the plastic colors and pasted them back on in the solved position. I heard about another guy who spray-painted it."

Like Chris Ottaway, Wiswell hasn't found his enjoyment diminished by learning the solution. For one thing, it's still complicated. Even with the printed answer, solving it can take hours. For another, there are all those other patterns to play with: plaids, crosses, concentric squares, even an alphabet laid out in the Bantam Books solution booklet.

Those of us who can't even solve one side of the cube, much less six, can take satisfaction in the knowledge that whatever pattern it is that we're stuck with, after hours of futile struggle, that pattern is just as rare and hard to achieve as any other.

Or, as wisdom comes to us, we may acquire the attitude of Joe Brinson, 18, a T.C. Williams senior who wanders into Chris Ottaway's living room just after she's polished off a demonstration run at two minutes and 24 seconds (her best is 2:05). Asked how he likes the cube, he says happily: "I hate it. I don't have the patience, so I don't play with it."