Since December, 20,000 teachers from kindergarten through 12th grade have introduced coding lessons, according to Code.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 policy makers 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.

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.

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 are projecting. And particularly for younger children, Dr. Soloway said, the activity is more like a video game — better than simulated gunplay, but not likely to impart actual programming skills.