I thought that made sense though - Anne with her PhD from Imperial starts with her quote from Einstein and ultra complex theoretical equation, but then the kids struggle (which was why they need extra tutoring), and Anne gets more and more frustrated as the maths gets simpler (so the intention is presumably is to show that it's Anne's teaching rather that is the problem), ending up with her being so frustrated that she gives them the answers - which then turn out to be wrong anyway!
I thought it was totally in keeping with the Anne character who has all the credentials and was Head of something at GSK, but actually gives the impression she used to work at Greggs. The wrong answers (particularly as it was the simpler maths) fitted with this, I thought.