Yo-yo master Dick Stohr gives a demonstration Saturday in his home at Westminister at Lake Ridge in Lake Ridge, Va. (Jahi Chikwendiu/The Washington Post)

The Cub Scouts in Pack 295 knew all about the two-dimensional world of the video game Minecraft, but they had never “pulled the puppy by the tail.” Some of them had never even held a yo-yo in their hands until Saturday, when Dick Stohr opened his box to reveal 48 brightly colored orbs.

“These are cool!” the kids gushed, reaching in. “Do they glow in the dark?” “Can we keep ’em?”

The scouts had come to sing carols at Westminster at Lake Ridge, a continuing-care retirement community in Prince William County. Afterward, they got a session with Stohr, a retired Navy captain who spent the past 20 years as a professional yo-yo master and has coached the Northern Virginia Senior Olympics yo-yoists and run their contests.

Before jumping into fancy tricks, Stohr, a tall, strapping 76-year-old with a brush of silver hair, started with safety tips. “Yo-yos come with a string. You’ve got something on the end of the string that can hurt someone.” He showed them how to form a slipknot and manipulate the toy, “using the middle finger, on the hand you write with.”

There was a time when practically every boy in America would have owned or at least had some idea of how to use a yo-yo. When Stohr was growing up in Cincinnati in the 1940s, demonstrators from the Duncan yo-yo company would come to town and leave boxes of the toys on the delicatessen counter for 25 cents each (or 35 cents for those with fake diamonds). Kids would practice their tricks, and when the demonstrators returned they would compete for a grand prize — a Schwinn bicycle — and Stohr was an avid participant.

But then yo-yos disappeared from his life.

“I put it away in high school and college because it wasn’t cool,” he said, sitting in the cottage he shares with his wife in front of a display case full of medals, trophies, books and an array of yo-yos collected over the years. “In 10 years of active duty, I never saw a yo-yo. But my mother had rat-holed a yo-yo from the old days, and every time I came home on leave, this yo-yo would appear and she’d say, ‘Do some tricks.’ And before she died, she made sure I got it.”

He held that one now — a wooden Duncan, painted salmon pink. He has restrung it a couple of times because the cotton strings on fixed-axle yo-yos wear out.

Stohr married and had two sons, retired from active duty, and worked as a Defense Department contractor in Northern Virginia. It wasn’t until the 1990s, after reading a Washington Post magazine story about the man who started the Yo-Yo Times, a newsletter for enthusiasts, that he became serious again. He began working with an Alexandria elementary school that had a yo-yo club, and in 1996, he quit his day job to start a business called “That YO-YO Guy,” bringing the yo-yo gospel to elementary schools and libraries across the Mid-Atlantic.

The ideal time to learn is around fourth, fifth and sixth grade, he said — old enough to master the skills but young enough so that the kids are not inhibited from trying something new in front of their friends. The focus required can help kids who have problems concentrating in school, he said, and the concepts can be educational.

“I used a whole bunch of kids’ toys to teach a science class,” Stohr said. “Gyroscopic stability, rotational inertia, distribution of mass, friction.”

Yo-yo mastery can also confer cachet. “If they learn to yo-yo in elementary school, they take it to high school as a cool thing they can do that no one else does. They take it to college as a stress reliever. And then they take it to clubs as a chick magnet.”

The yo-yos in Stohr’s cabinet tell stories. One set a record for the longest “sleep” time; one was made for him by a friend out of rare cocobolo wood. An oversize Neiman Marcus leather yo-yo was made in France; a slim iron one advertises Billiken shoes; a pair of tiny ones plated with 24-karat gold were given out at a meeting of Duncan pros.

A basic yo-yo like the ones Stohr uses for demonstrations costs $7. But fancy ones can cost more than $100; the top price is $450, for a Duncan yo-yo with individually dynamically balanced titanium halves, powder-coated, with a concave ceramic ball-bearing. “It’s a limited run of about 100, and they sell out every year.”

Stohr retired from the yo-yo business earlier this year; he is now reinventing himself again as a wood-turner, using a lathe to make wooden pens, bottle stoppers, honey drippers, purse mirrors and spurtles — an Irish oatmeal stirrer.

But he is still ready to share his tricks when called upon, and on Saturday, the kids, including a few girls, looked on, wide-eyed.

He walked the dog: the yo-yo dropped from his hand and rolled along the carpet obediently, like a pet on a leash. He rocked the baby: zip, zip, zip — the string formed a gossamer structure and the yo-yo swung from it like a cradle. Around the world? For that one, it shot out in front of him, arced up behind him and rolled back to its starting point.

And, of course, the impressive pulling the puppy by the tail: a way to get the yo-yo to wind itself on the ground.

“This is really cool,” said Emma Berliner, 10, whose younger brother Kyle is a member of the troop. “I didn’t really know that you could do tricks like this at home.”

What about taking the tricks to school? “That would be epic,” said Christopher Kirby, 7, a troop member.

Although Stohr has tried to drum up interest in a yo-yo team in the Virginia and National Senior Olympics, he has had little response. “One of the issues when you get into the retired community is many fingers are not capable of the dexterity required, or it hurts with the string,” he said.

But on Saturday, he ended up with a couple of older converts: the two scoutmasters, who got their own yo-yos. When Robert Lewis got home, he and his son Raymond, 9, practiced the new skill together.

“There’s not a lot of kids these kids’ ages that really get hands-on stuff anymore,” Lewis said. “It’s all computers and video-game consoles.”

But now, he said, “He wants to practice rather than run down to the console. The first thing when we got home, he said, ‘I can do this, I can do that.’ ”