Nathan (Asa Butterfield), right, has his pick of the ladies — all two of them — at the math competition in “A Brilliant Young Mind.” (Samuel Goldwyn Films)

The hero of “A Brilliant Young Mind” is loosely based on a boy who director Morgan Matthews featured in “Beautiful Young Minds,” his 2007 documentary about participants in the International Mathematics Olympiad. Despite that real-world back story, this coming-of-age drama strives more for amiability than authenticity. While the performances are convincing, the script is packed with too-good-to-be-true developments.

Nathan (“Hugo” star Asa Butterfield) is a British math prodigy who’s on the autism spectrum. If his social awkwardness weren’t trouble enough, Nathan is also haunted by memories of watching his beloved father die in the seat next to him during a car crash. His surviving parent (ever-bubbly Sally Hawkins) is devoted, but can’t connect the way Dad could.

Assisted by a teacher (Rafe Spall) with abundant problems of his own, Nathan eventually gets a shot at the Olympiad. The teenager is sent to math boot camp in Taipei, Taiwan, a city the boy and the movie find fascinating.

There’s one girl each on the British and Chinese squads, and they both fall for Nathan. That’s great for his confidence, but confounding to the skeptical viewer. What’s more, the kid teaches himself Mandarin, seemingly overnight, and picks up piano without a lesson. Nathan is implausibly brilliant at almost everything.

Boosted substantially by the naturalistic Taiwan sequences, “A Brilliant Young Mind” is less stuffy than the usual cinematic ode to British smarts and schooling. But that still can’t save this tale of eccentric genius from being profoundly conventional.

Jenkins is a freelance writer.

Unrated. At Landmark’s Bethesda Row Cinema and Cinema Arts Fairfax. Contains obscenity. In English and occasional Mandarin with subtitles. 112 minutes.