A new test shows the literacy and numeracy problems of prisoners to be much worse than previously thought.
The Burt Word Recognition Test found 2% of prisoners need literacy help and 17% need numeracy help.
A new screening tool, developed by the Ministry of Education, was also trialed recently on 197 new prisoners.
It found 90% needed literacy help and 80% were not functionally numerate.
The Department of Corrections says the two tests measure different levels of need and the new test is much more sophisticated.
The department recently spent $3.5 million on literacy and numeracy courses at all prisons.
