A local man found the correct number in minutes, according to the local man.

The number is the share of Providence's rental units that a rent-stabilization ordinance would cover. The city's chief financial officer had put it at fewer than 44 percent. The council's consultant, writing a fiscal note, had assumed 60 percent, or 48,000 of 80,000 units, and later called that generous.

His method was to look. He took the city's 2025 property tax roll, which is public, and the assessor's parcel file, which is also public, and laid one over the other. Ninety-six percent of residential parcels matched. He counted the rental units, left out the apartment the owner lives in, and took the ordinance's exemptions one at a time. Before the last one it came to 69 percent. The last one is deed-restricted affordable housing, which the tax roll lists without saying how many apartments it holds. Counting those, the share falls to between 60 and 65 percent.

So the consultant's guess was about right, and now there are parcels under it.

The city's 44 percent requires something more. For it to hold, no one who owns a two- or three-family house in Providence can live in it. Every unit in an owner-occupied building has to be a rental, including the one with the owner in it, and then every one of them is exempt. The landlord is counted as his own tenant and then exempted from himself.

The local man said it was a mistake a 24-year-old would not make.

Asked for the method behind the 44 percent, the mayor's office said it had given everything it could, and that questions about coverage were best put to the City Council, which drafted the ordinance. The 44 percent is the chief financial officer's. The Council does not have the chief financial officer's method. The chief financial officer has not said what it is.

Asked how he had done it so quickly, the local man said he looked. Asked why the city had not, the city said to ask the Council.