New Zealand's foremost mathematician has spoken out against the way maths is taught in schools, saying children need to know basic arithmetic before they try to start problem solving.
Sir Vaughan Jones, winner of the Fields Medal - the maths equivalent of the Nobel Prize - told the Weekend Herald that children had to do "lots and lots of exercises" to build up familiarity and confidence before they moved on to more advanced concepts.
His comments follow those of Education Minister Hekia Parata, who said last weekend that she was "extremely concerned" by results from an international survey of Year 5 children in December, which showed half could not add 218 and 191.
Ms Parata said she had asked officials to find out more about the traditional methods of Auckland maths educator Des Rainey, who discovered most Year 5 and 6 children tested at an Auckland school could not quickly answer simple multiplication or division questions but improved rapidly after practising his simple arithmetic drills.
Sir Vaughan, who is based at Vanderbilt University in Tennessee in the United States, said he was not familiar with the latest test results but he stood by comments he made last year in Made in New Zealand, a book of interviews with top achievers.
In the book, Sir Vaughan said it was highly debatable whether we were teaching young children maths in the best and most effective way.
"People are trying to teach kids broad concepts too early when, in fact, the best way to learn is the complete opposite.
"It is really important that kids learn how to multiply and add, to the point where they are certain they will get the right answer if they do the steps right. Then, and not before, they start to see more aspects of the structure. It is a slow process built on understanding each step."
He disagreed with University of Auckland mathematics lecturer and curriculum reformer Peter Hughes, who said children did not need to learn long multiplication or division any more because they could use calculators.
Sir Vaughan said it was sensible to use a calculator for complex multiplication but ridiculous to say the skill was no longer important because the same reasoning could be applied to adding and even counting.
"So where are we supposed to draw the line and say 'you don't need to know how to do this because computers can do it for you'?"
He said that since the 1980s New Zealand had slavishly followed California in abandoning perfectly functional maths methods built up over thousands of years.
Several teachers who contacted the Weekend Herald after last week's story said they used traditional maths-teaching methods despite the change in policy.