McKenna Grace is good here as the young "Mary" who is clearly rather gifted with it comes to mathematics. Her teacher "Miss Stevenson" (Jenny Slate) cottons on quite quickly and after an altercation on the school bus, her uncle "Frank" (Chris Evans) with whom she lives after the suicide of her mother (his sister) is being sold the virtues of a new school with a much more focussed agenda. "Frank" think she is better growing up surrounded by ordinary kids but a bit of interference from the disappointed head teacher finds him face to face with "Evelyn" (Lindsay Duncan). She is the grandmother of ...