'Leave tables to chants'.
Studies with children revealed that those who used memory solved problems faster and more accurately.
Those who used the counting method - using blocks or fingers - were the slowest and least accurate.
The implications for the teaching profession was that rote learning was needed for learning mathematical facts, Dr Sylvia Steel told the BA Festival of Science at Exeter University, Devon.
'If I had my way, children would know their tables,' said Dr Steel, research associate at Royal Holloway University, London.
'But it is important children should understand what they are doing than just chanting,' she said.
Rote learning and other auditor methods had given way over the past 30 years to more visual methods which aimed to emphasise understanding or arithmetic concepts.
'Learning multiplication tables was, for a while, almost extinct in State schools because it was considered boring and unlikely to lead to understanding,' said Dr Steel.
But many teachers taught children by rote 'behind closed doors', she said.
The National Curriculum directed that addition, subtraction and multiplication facts should be taught.
But teaching methods emphasised number patterns and calculation procedures rather than rote learning.
A bigger study was now planned which would include investigations into ways of helping children develop automatic retrieval.