"We'd prefer to see the numeracy strategy as something you opt into rather than something you opt out of."
The literacy programme, while popular with many schools, has also been criticised as "too prescriptive". It has been presented as "non negotiable" by ministers.
The numeracy strategy has taken a different tack. "What's compulsory is for schools to audit their existing practice," said Professor Reynolds. "To look at our technology and to see if any of it is useful. It's then a matter for the school, its results, its context."
The numeracy strategy appears to have a simpler task. Maths results seem easier to improve than reading scores, possibly because they start from a worse position. In the past three years, key stage 2 maths results have improved by 12 percentage points. Literacy has improved by only six points.