Under pressure from an oversight panel, Los Angeles school officials have sharply reduced the number of iPads they say are needed to carry out new state standardized tests.

The change adds up to a $25-million savings, but examination of the testing plan has raised more questions about the $1-billion effort to provide the devices to every student, teacher and school administrator in the nation's second-largest school system.

The issue surfaced at a Wednesday meeting of the School Construction Bond Citizens' Oversight Committee, which reviews L.A. Unified's spending of voter-approved bonds to build and modernize campuses. The iPad program is being funded primarily from bonds.

While the testing this spring is merely a trial run — the results won't count — participating schools must take part by computer.

Officials have aimed for all L.A. Unified students to use iPads on the tests, but the districtwide rollout has been delayed. In addition to iPads already allotted to schools, administrators estimated they would need 67,480 more devices solely for the testing.

That estimate first was challenged in November, when bond oversight chairman Stephen English noted that he had reached a lower number when using the formula the district said it had applied to calculate its iPad needs.

The district's chief strategy officer, Matt Hill, responded that other factors — which were not part of the formula — had led to the higher count. The district stuck to its number and sought authorization from the Board of Education, which has the final say.

"I believe it is imperative that all of our students are prepared and able to participate in this important testing next spring," L.A. schools Supt. John Deasy wrote in a report to the board ahead of a planned meeting this month. "Staff will continue to work diligently to purchase only the number … necessary to successfully conduct testing."

Then board member Marguerite Poindexter LaMotte died, contributing to a postponement that allowed the oversight committee another review.

This time, the district presented an analysis that found only half as many iPads would be needed for 2014. The larger number was for 2015, when students would be taking the full, actual test.

But even the smaller figure was challenged Wednesday.

It included about half a dozen schools that already had iPads for all students, committee consultant Thomas Rubin said. Also included were primary centers that serve students only through second grade — the state testing begins in third grade. In addition, the list contained schools with extensive technology already in place, Rubin said.

In the end, the committee endorsed buying about 38,000 devices for testing, but asked for more evidence to justify that number. The panel also approved buying detachable keyboards for use with the iPads during testing.

The school district recently distributed surveys to principals about older computers currently being used on their campuses, many of which can accommodate the new tests. Principals, however, may lack the time and qualifications to assess their current computers. Some district technicians have volunteered to help during the holiday break, Rubin said.

Senior L.A. Unified staff have put forward various reasons for buying as many iPads as possible prior to testing. Existing computer labs, for example, may lack enough working machines to accommodate a full class at once.

And if labs are used for testing, then they would not be available for instruction or for students to use for term papers and other projects, noted committee member Quynh Nguyen.

"It is a logistical nightmare, especially in secondary schools," Nguyen said. "Those computers are under heavy, heavy use."

howard.blume@latimes.com