(at around 14 mins) In the classroom scene, Martin announces that he believes in the number pi, and explains that by this he means the golden section, related to the Fibonacci sequence. The goof is that this number is universally referred to as phi, not pi, which is reserved for the ratio of the circumference to the diameter of a circle.
Towards the end when the bus with the kids crashes, first you see it totally engulfed in flames but then when they go back to it a minute or two later only the front of the bus is on fire and the rest of the bus is still white and not burned.
(at around 20 mins) During the camera panning, when Martin is riding his bike and parks it by the fence and passes the tree, the camera cues anew. Martin's arm nearest the camera after he exits the tree does not match the way it was positioned when he entered behind the tree.
Bormat's Last Theorem should be Fermat's Last Theorem. It is very surprising since the script gives fairly accurate details of its proof down to the modular forms and elliptic curves. Further, it was solved by Andrew Wiles, not 'Henry Wilkins'.