The phrase "a contribution of three" is correct and usable in written English.
It can be used when referring to a specific amount or number that someone is contributing to a particular context, such as a project, discussion, or event.
Example: "The committee received a contribution of three from each member to fund the upcoming event."
Alternatives: "a donation of three" or "an input of three".
According to Parker, Volpe asked him for a "contribution" of five million dollars toward launching Provenance.
The man had just received a letter demanding a "contribution" of seven million pesetas, about forty thousand dollars, "on behalf of the struggle for the independence of the Basque people".
On park Avenue, Mrs. Mary Lasker had started things back in 1947 with a contribution of twenty thousand tulip bulbs for planting in the malls between 34th and 39th Streets.
The Athenians needing money for the siege, although they had for the first time raised a contribution of two hundred talents from their own citizens, now sent out twelve ships to levy subsidies from their allies, with Lysicles and four others in command.
At last week's convention, the gunmaker made a contribution of four million dollars to the NRA Institute for Legislative Action, the organization's political arm.
For GST-Q22 and GST-Q41 or even for GST samples under aggregating conditions, a contribution of two different particle populations was observed always.
In the case of Figure 4 this produces a contribution of two pairs for the first occurrence of y, and one for the second.
We briefly mention here (the biochemistry of PDT has been extensively studied by several other investigators and various publications exist in the medical literature) that in PDT there is a contribution of two reaction mechanisms (Type I and Type II) which result in damage mechanisms that depend on oxygen tension and photosensitizer concentration.
It showed a contribution of AUD$1.8 million (USD$1.9 million).
The 85 billion euro ($112 billion) total includes a contribution of 17.5 billion euros by the Irish government itself through money it has already raised.
