The state of Texas has dropped a math curriculum that is mandated for use in New York City schools, saying it was leaving public school graduates unprepared for college.

The curriculum, called Everyday Mathematics, became the standard for elementary students in New York City when Mayor Bloomberg took control of the public schools in 2003.

About three million students across the country now use the program, including students in 28 Texas school districts, and industry estimates show it holds the greatest market share of any lower-grade math textbook, nearly 20%. But Texas officials said districts from Dallas to El Paso will likely be forced to drop it altogether after the Lone Star State’s Board of Education voted to stop financing the third-grade textbook, which failed to teach students even basic multiplication tables, a majority of members charged.

One board member, Terri Leo, who is also a Texas public school teacher, called the textbook “the very worst book that we had submitted.” This year, the board of education received 163 textbooks for consideration.

The board chairman, Don McLeroy, said the vote was part of a larger effort to prepare more Texas students for college. “We’re paying millions of dollars to the publishing industry,” Mr. McLeroy said. “We might as well get something back.”

The vote leaves some doors open for Everyday Math. As long as Texas districts use their own money, and none from the state, they can still purchase it, and they can still use state funds to purchase first, second, fourth, and fifth-grade Everyday Math textbooks. But state officials, including several who support Everyday Math, said they expect districts will drop it, since most use one program for all of the elementary grades and all prefer to finance their books using state funds.

A board member who voted against the ban, Mavis Knight, described what will happen as a “domino effect” across the state.

Some advocates said the effect could be even greater, reshuffling a standstill in a national fight known as the math wars. While supporters of Everyday Math applaud it and other so-called progressive programs for their emphasis on problem-solving and group work, opponents charge that the best way to teach math is still through rote memorization of facts, calling anything else “fuzzy math.” A recent entry by the federal Department of Education into the debate cleared up little, judging Everyday Math more effective than some more traditional programs but calling its impact still just “potentially” positive.

Since Texas is one of the country’s largest buyers of educational textbooks, the advocates said its decision could force textbook publishers and school districts to rethink their position in the battle.

“What happens in Texas has ramifications for the whole country,” a longtime Texas activist for traditional curricula, Donna Garner, said. “It’s a huge movement.”

Texas officials said Everyday Math’s publisher, McGraw Hill, began scrambling to keep its curriculum on the state’s okay list the minute board members indicated they might vote it off. After concerns were first raised at a long meeting last Thursday, McGraw Hill officials arrived the next morning at 9 a.m. sharp with seven full sets of additions to the text, including new worksheets and teacher guides, state board members who attended the meeting said.

“I think they were in a state of shock, like those of us who were on the non-prevailing side,” Ms. Knight said. “I think they were truly mystified.”

A spokeswoman for McGraw Hill, Mary Skafidas, called Everyday Math a “proven rigorous program,” and pointed out that the publishing company also offers many alternative curricula districts could choose to buy instead.

New York City’s Education Department also stood by the program. A spokeswoman, Maibe Gonzalez Fuentes, said the improvements for fourth-graders shown on a national math test last week testify to its success. “We continue to study developments in math education, both in this country and internationally, and we are convinced we are on the right track,” she said.

But advocates who have ridiculed Everyday Math since the schools chancellor, Joel Klein, created a task force that eventually picked it said they hoped New York City could take a lesson from Texas.

“Our educators are making choices which ultimately have the consequence of barring a huge number of kids from high-paying jobs,” a computer science professor at New York University, Alan Siegel, said. “It’s that simple, and I applaud Texas for standing up to this.”

Mr. Siegel, who has advised the city schools and a federal group on math, is one of several New York professors who have opposed Everyday Math, calling it poor preparation for the kinds of college courses they teach.

Not all New York City elementary schools follow the curriculum; some — including many schools in District 2 — have obtained waivers exempting them from the mandate to use it.