The New Zealand Initiative report said a $70 million government policy called The Numeracy Project had over-complicated maths teaching, confusing children with multiple methods of learning multiplication and addition. It advocated a return to more rote learning.
Dozens of parents emailed the Herald in support of memorising times tables and using column addition following the story, saying they were shocked at how slowly their children were learning.
Ms Parata said maths had been a long-term challenge in New Zealand, and the current debate was about the way basics were learned, with schools needing to find a balance between learning basic facts and creative strategies.
She said it would be addressed "by raising the quality of teaching and ensure that resources are shared".
The Ministry of Education's deputy secretary for student achievement, Dr Graham Stoop, said there were multiple contributing factors to a decline in mathematics achievement, and attributing this to a single factor didn't take into account other influences on student achievement.
"It is possible that the way the [Numeracy Project] was applied may have varied between schools and some may have de-emphasised basic maths facts more than intended. However, the 2007 New Zealand Curriculum clearly includes them."
NZEI head Louise Green said it had been saying for a long time that better training was needed - both on the job and in initial teacher education.
