Numbers speak to the star of “Becoming Warren Buffett” — the HBO film that will premiere at the Museum of Modern Art on Thursday — but words do, too.

It was by way of a handwritten letter, in fact, that director Peter Kunhardt interested Buffett in a movie project that lasted longer than two years.

The collaboration not only included Kunhardt’s two sons as producers, but also Buffett’s three children as interview subjects.

The Oracle of Omaha was completely open about his life when he wanted to be, but the questions he refused to answer were invariably the most telling.

“We realized we needed the voices of others,” Kunhardt said at a screening last week.

The extra voices combined — especially those of Buffett’s deceased first wife, Susie; his daughter, Susan; and Berkshire Hathaway partner Charlie Munger — make “Becoming” as much a love story as it is a business story.

Particularly moving is Buffett’s first trip to visit his wife after she abandoned him to begin anew in San Francisco.

“He said, ‘This really is, this is your city,’ ” Susie recalls in an interview shortly before her death in 2004.

“I am so drawn to color and light and form and nature that he thought it was a good place for me,” she said.

Buffett also considers the story moving — so much that he’s expected at the MoMA premiere this week, which will require a rare visit to the city he gave up in the mid-1950s to return to his native Nebraska.

Only this time, Manhattan can offer up two of Buffett’s favorite outlets — the Dairy Queen on 14th Street and a soon-to-open See’s Candies on 8th Street — both of which the Oracle’s Berkshire Hathaway owns.