The White House unveiled its own version of the new math yesterday with an announcement that it had saved the taxpayers $166,500 a year by handing out $400,000 a year in pay raises to 48 staff members.

As outlined in a dead-pan press release to skeptical guffaws in the White House press room, President Carter's scheme of savings through spending works this way:

It saves $13,500 by raising the salaries of nine presidential assistants, including press secretary Jody Powell, from $44,600 to $56,000 instead of the maximum authorized level of $57,500.

It saves $10,500 by raising seven special White House assistants from $42,000 to $51,000.

It saves $16,500 by raising 11 other assistants from $39,000 to $48,500, instead of $50,000.

It saves $126,000 by raising 21 other staffers to $42,500 instead of $48,500.

The kicker in the unique economy plan, which Powell finally acknowledged under questioning, is that it carries a net price tag of $400,000 beyond current White House salary spending.

The inner circle of nine top assistants whose pay will be increased to $56,000 are Powell, Hamilton Jordan, Jack Watson Jr., Zbigniew Brzezinski, Margaret (Midge) Constanza, Stuart Eisenstat, James R. Schlesinger Jr., Frank Moore and Robert Lipshutz.

The subject of White House salaries has been a matter of tender concern to the President because of his desire to set a frugal example for the rest of the government. Earlier this week Powell announced that the new White House salary structure would be "substantially reduced" from authorized levels:

Powell said that Rosalynn Carter's staff members also will receive salary increases but that they were not included in the package announced yesterday. Nor were aides to Vice President Mondale included in the announcement.

Moreover, most of the White House staff below these top levels will receive no pay raise at all, according to deputy press secretary Rex Granum. The White House pay raises, like those elsewhere in government this year, applied only to the top levels.

The complete White House announcement on the pay raises said:

"At the President's direction, a plan was devised to reduce the authorized salary increase for White House staff. The President felt it was important for the White House to set an example in holding down increases in executive level salaries in the federal government.

"He sees this action as complemetary to the substantial reduction in total numbers of White House staff which took place at the beginning of the administration."