UPDATE 4:00 p.m.: It took some number crunching, but the data Madigan sent us — all of which originated with District's Department of Housing and Community Development — shows 11,000 completed or preserved affordable housing units. (A unit is preserved when the District government purchases it or otherwise intervenes to prevent it from shifting to market-rate housing.)

The spreadsheet shows 6,535 affordable housing units for fiscal years 2007 to 2010. The PDF shows completed affordable housing units since fiscal year 2006, as well as projections for fiscal years 2011 and 2012.

If we add up the spreadsheet total and the PDF total from Fenty's term, we get 12,598 units. We're trying to get more context for this information — particularly on the spreadsheet numbers — but we're awarding the Fenty campaign a tentative Honest Abe.

UPDATE 1:35 p.m.: Madigan sent us the campaign's backing. It comes in the form of a spreadsheet and a PDF. We're looking them both over, and will let you know when we come to a conclusion.

For now, let's point out why this matters to Fenty. The Fenty campaign is suffering from the perception that it doesn't care about poorer, blacker neighborhoods, and that the incumbent mayor is all about "dog parks." If Fenty has built 11,000 affordable housing units, it could undercut that argument.

ORIGINAL: We're going to try something new today on The Facts Machine. We're going to update this fact check throughout the day, showing you how the piece evolves  as we gather more information. Plus, if you have any evidence that could sway us, leave a comment or tweet @tbdfactsmachine.

What we're looking at today is Adrian Fenty's claim that his administration "Created or preserved 11,000 units of affordable housing," which has been a regular talking point for the Fenty campaign.

We contacted Fenty campaign spokesman Sean Madigan late yesterday afternoon, and he said he would gather the campaign's evidence as soon as possible. As of midnight, we hadn't heard from him.

Fenty has already slipped on this talking point once during the campaign. Before construction was finished on The Facts Machine, Fenty said his administration had "built 11,000 units of affordable housing." The Washington Post's Tim Craig and Nikita Stewart astutely called out the mayor, pointing out that data provided to them had only shown 5,000 constructed housing units.

That left 6,000 units unaccounted for. We'll try to track them down, but for now we have Insufficient Evidence to Rule.