There might be unintended consequences which Sunak wouldn't like, indeed there may, growstuff. I can't tell you how many times I shouted at the TV when NIC was raised to 13.5 and was being reported as a 1% increase, when it was in fact in excess of 10%. Maybe people will also realise that a drop in inflation does not mean that prices will drop, it just means that they will not rise by so much.
As someone who was taught Maths by a teacher far too clever to teach 11 year olds, I lost my way mathematically for years.
I am bemused when people laughingly claim to be 'rubbish at maths' but would not make the same claim about their literacy. To an extent, I can see Sunak's point, but like all of his great plans, there has been no thought as to how these great advances in maths teaching will be achieved.