MILL VALLEY, CALIF. — Seven-year-old Jordan Lisle, a second-grader, joined his family at a packed after-hours school event last month aimed at inspiring a new interest: computer programming.

   “I’m a little afraid he’s falling behind,” his mother, Wendy Lisle, said, explaining why they had signed up for the class at Strawberry Point Elementary School.

   The event was part of a national educational movement in computer coding instruction that is growing at Internet speeds.

   Since December, 20,000 teachers from kindergarten through 12th grade have introduced coding lessons, according toCode.org  , a group backed by the tech industry that offers free curriculums.

   In addition, some 30 school districts, including New York City and Chicago, have agreed to add coding classes in the fall, mainly in high schools but in lower grades, too. And policymakers in nine states have begun awarding the same credits for computer science classes that they do for basic math and science courses, rather than treating them as electives.

   There are after-school events, too, like the one in Mill Valley, where 70 parents and 90 children, ranging from kindergartners to fifth-graders, huddled over computers solving animated puzzles to learn the basics of computer logic.

   It is a stark change for computer science, which for decades was equated with trade classes like wood shop. But smartphones and apps are ubiquitous now, and engineering careers are hot. To many parents

   — particularly ones here in the heart of the technology corridor

   — coding looks less like an extracurricular activity and more like a basic life skill, one that might someday lead to a great job or even instant riches.

   The spread of coding instruction, while still nascent, is “unprecedented — there’s never been a move this fast in education,” said Elliot Soloway, a professor of education and computer science at the University of Michigan.

   He sees it as very positive, potentially inspiring students to develop a new passion, perhaps the way that teaching frog dissection may inspire future surgeons and biologists.

   But the momentum for early coding comes with caveats, too. It is not clear that teaching basic computer science in grade school will beget future jobs or foster broader creativity and logical thinking, as some champions of the movement project. And particularly for younger children, Soloway said, the activity is more like a video game

   — better than simulated gun-play, but not likely to impart actual programming skills.

   Some educators worry about the industry’s heavy role: Major tech companies and their founders, including Bill Gates and Facebook’s Mark Zuckerberg, have put up about $10 million for Code.org  . The organization pays to train high school teachers to offer more advanced curriculums, and, for younger students, it has developed a coding curriculum that marries basic instruction with video games involving Angry Birds and hungry zombies.

   The lessons do not involve traditional computer language. Rather, they use simple word commands — like “move forward ” or “turn right” — that children can click on and move around to, say, direct an Angry Bird to capture a pig.

   The movement comes with no shortage of “we’re changing the world” marketing fervor from Silicon Valley.

   “This is strategically significant for the economy of the United States,” said John Pearce, a technology entrepreneur.

   He and another entrepreneur, Jeff Leane, have started a nonprofit, MV Gate, to bring youth and family coding courses developed by Code.org   to Mill Valley, an affluent suburb across the Golden Gate Bridge from San Francisco.

   Parents love the idea of giving children something to do with computers that they see as productive, Pearce said.

   “We have any number of parents who say, ‘I can’t take my kid playing one more hour of video games,’” he said. But if the children are exploring coding, the parents tell him, “‘I can live with that all night long.’”

   The concept has caught on with James Meezan, a second-grader. He attended one of the first “Hour of Code” events sponsored by MV Gate in December with his mother, Karen Meezan, the local PTA president and a former tech-industry executive who now runs a real estate company.

   Her son, she said, does well in school but had not quite found his special interest and was “not the fastest runner on the playground.” But he loves programming and spends at least an hour a week at CodeKids, afterschool programs organized by MV Gate and held at three of Mill Valley’s five elementary schools.

   Computer programming should be taught in every school, said Hadi Partovi, the founder of Code.org   and a former executive at Microsoft. He called it as essential as “learning about gravity or molecules, electricity or photosynthesis.”

   Among the 20,000 teachers who Code.org   says have signed on is Alana Aaron, a fifth-grade math and science teacher in Manhattan. She heard about the idea late last year at a professional development meeting and, with her principal’s permission, swapped a two-month Earth sciences lesson she was going to teach on land masses for theCode.org   curriculum.

   “Computer science is big right now — in our country, the world,” she said. “If my kids aren’t exposed to things like that, they could miss out on potential opportunities and careers.”

Students and parents learn programming basics at a free event put on by Code.org   at an elementary school in Mill Valley, Calif. An accelerating national push to emphasize computer science in schools has included child-friendly coding lessons. JASON HENRY / NEW YORK TIMES