D.C. school system officials will order tens of thousands of new science and social studies textbooks months earlier than usual for the fall semester, attempting to avoid the fiasco of 2005 when widespread delivery delays forced some students to use old books well into winter.

The Board of Education adopted new science and social studies textbooks at a cost of $7.1 million Wednesday night. Full implementation of new academic standards was delayed last year when the books were not ordered in time for the fall 2006 semester.

Officials said they will order the science and social studies books immediately for a spring delivery, giving teachers plenty of time to review the material before the fall.

"Children deserve to have their books on time," Abdusalam H. Omer, the system's chief business operations officer, said yesterday. "We are ahead of schedule," he added. "The books should come in before the school year ends -- we're shooting for May 1."

In December 2005, the school board ordered Superintendent Clifford B. Janey to conduct an audit of the textbook ordering process after The Washington Post reported that many teachers and parents complained that students lacked reading and math books months after the semester had begun.

Officials said a preliminary audit showed that 14 percent of schools had not received all their books. They blamed inaccurate student enrollment projections, the lack of a computer system to track the shipments and the size and late date of the order -- 450,000 books had been ordered in July 2005 for an Aug. 29 delivery.

Then last August, Janey postponed a purchase of new science and social studies books when it became clear that they could not arrive in time for use with new learning standards. He opted to use the old textbooks for one more year. As a result, officials said, they decided that sixth- and seventh-graders would continue to use some of the old social studies standards for another year because some of the new standards could not be implemented without the new texts.

As part of the contract for the science and social studies texts, the book companies will have to pay a fine amounting to 20 percent of the order if the books arrive late.

"It would be devastating if we could not get the textbooks to bring the new standards to life," Wilma F. Bonner, assistant superintendent for curriculum and instruction, told the school board. "It would be a travesty not to get [the books] we promised the students last year."

In 2005, the system ordered 450,000 math and reading books. But this year, school officials said, they intend to order about 40,000. They said they will replace only those books that are at least five years old.

The school board awarded science book contracts to McGraw-Hill; Delta Education; Holt Rinehart and Winston; and Harcourt School Publishers. It awarded social studies book contracts to McDougal Littell; McGraw-Hill; Harcourt School Publishers; and Prentice Hall.