Children whose knowledge isn't up to scratch when they start school should be tested so the funding they require can be measured, a new report on child poverty says.
Children in poverty "do not leave their daily life circumstances at the school gate", says John O'Neill, author of the latest report from independent charity The Child Poverty Action Group.
Developing a "culturally appropriate" measure of a new entrant child's cognitive, behavioural and developmental needs that can inform school funding decisions is one of 10 recommendations set out in the report, which says there are now 285,000 children with varying educational needs living in daily poverty.
"Educational researcher Cathy Wylie has summarised the magnitude of these differences: Average 5-year-olds' reading scores in decile one schools were almost half those of children in decile 7 to 10 schools, and mathematics scores were on average a third lower," O'Neill said.
Deciles represent the average number of socially and economically disadvantaged students at a school, with decile 1 being the most disadvantaged and decile 10 the least.
Lower-decile schools found it difficult to "reduce inequalities of educational outcome" without extra money to make up for the fact that higher-decile schools sourced more cash from their school community, O'Neill said.
Teachers could already identify students with learning problems - the challenge was getting the funding to help fix it, Post Primary Teachers' Association president Angela Roberts said.
"The thing we like about decile funding is that it acknowledges some schools require greater resources than others."
But taking a step back and reassessing how much it cost to educate a child and then adding in all their other needs would be a better funding system, she said. "Funding is about the needs of a kid, not the location of a school."
Education Minister Hekia Parata publicly criticised the decile system last year, saying it needed to be scrapped because it was sometimes used "to explain or excuse everything".
She described the ratings, introduced in 1995, as well intentioned but "clumsy".
The Ministry of Education has been asked to explore new options for funding but to date the minister has not announced any progress.
NZEI president Judith Nowotarski said school funding systems had not kept up with the country's evolving needs, particularly poverty.
Other recommendations set out in the report include reducing class size and increasing pay for teachers in low-decile schools, free breakfast and lunch programmes, before and after school holiday clubs, abandoning national standards and providing free NCEA and scholarship exams to low-decile schools.