The phrase "at a sum" is correct and usable in written English.
It can be used when referring to a specific total amount, often in financial contexts or calculations.
Example: "The project was completed at a sum of $50,000, which was within our budget."
Alternatives: "for a total of" or "at a total amount of".
How would one even begin to arrive at a sum for the reparation payments?
Cap the amount that tenants can be charged as security deposit at a sum equal to five weeks' rent.
It said: Using somewhat bullish assumptions we arrive at a sum of the parts total for Reckitt of 4537p, which leaves little upside.
The reduced level would mean unemployed households' total benefits income would be capped at a sum far less than median earnings.
Those beholding natural landscapes made the switch to deferred gratification at a sum, known as the indifference point, that was 10% below those who scanned cityscapes.
By the autumn of 1882, when the estate lawyers assembled in an office in Manhattan to take stock of the recently deceased man's estate, they calculated his assets at a sum worth the equivalent today of $750 million.
The Garden of Eden, his last, unfinished book, published posthumously, was a daring, heroic attempt at a summing up on a grand scale.
At a summed interaction value less than −0.7 there is no longer a local maximum, and CG methylation has a purely negative effect on gene expression.
They had forecast the drug's peak sales at $250 million to $500 million, a sum that would have been shared with H. Lundbeck.
Bail was set at $1 million, a sum that she was unable to meet, and so she remained in jail.
Judge Mullins, however, set bail at $3,500, a sum Mr. Taylor was unable to raise until Aug. 10, when a friend obtained a bond to free him.
