Inspired by the director's documentary Beautiful Young Minds, X + Y is described as "a rites of passage drama about a teenage prodigy’s journey to the Mathematics Olympiad, and his quest to find a formula for love."
Butterfield's role in the project is unclear at this time, but going off on the information in the article, it seems likely he'll be portraying the young math prodigy Nathan. The character's mother and love interest have both yet to be cast.
“The film has shades of Billy Elliot, which I was involved in commissioning," origin head David Thompson told Screen. "It is a very uplifting and affirmative love story about two hyper-clever and extraordinary teenagers from very different worlds.” (Screen Daily)
The film is due to shoot this summer largely in England, with possible locations also in Taiwan and China.