Donning white hard hats for their tour of the Federal Reserve’s construction site on Thursday, President Trump and Fed Chair Jerome Powell almost immediately began squabbling over the cost of the central bank’s renovations of two historic buildings.

When Powell fact-checked Trump’s claim that the $2.5 billion price tag had swelled to $3.1 billion, Trump pulled a piece of paper from his suit jacket, handing it to Powell. The Fed chair put on his glasses and studied it. “You just added in a third building,” Powell said, referring to an adjacent office building the Fed finished refurbishing in 2021.