Education Minister Huw Lewis has demanded that schools here show greater urgency to improve standards of numeracy, in line with Welsh Government agenda.
The Welsh Government introduced the National Literacy and Numeracy Framework in 2012, which is designed to get both key areas being taught in other subjects, across the curriculum.
Annual numeracy tests for pupils aged 7 to 14 began in May 2013.
Estyn praised the initiatives, for raising expectations, and says time spent training has increased.
However, the education watchdog says numeracy is still not seen as a priority in a minority of schools - and only half have developed appropriate plans for improving pupils’ numeracy skills across the curriculum.
Huw Lewis said: "we do need to make sure every school pays much more than lip service to these initiatives."
The Education Minister has announced a new national conference for heads of maths at Welsh schools, on 28 January next year, to share best practice and hear from international experts.
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