The Stanford Tizard scheme has already been tried in 10 UK schools. They introduced algebra from Year 1 and reported it gave pupils a greater ability to handle the curriculum.
Now they are looking to expand the project to 30 schools, including some in the US and South Africa.
Dr Ian Benson, the project leader, said: "The more children, teachers and schools contribute to our work, the greater the proven successes and the more children's creativity is tapped."
The Stanford Tizard approach involves using coloured rods to represent abstract concepts, a technique first pioneered by the Belgian teacher Georges Cuisenaire.
Organisers of the scheme claim it has had an impact on policy in the US, where officials are drawing up a new maths curriculum in collaboration with the National Council of Teachers of Mathematics.
Previously US maths policy was based on the work of Swiss developmental psychologist Jean Piaget, who claimed that algebra should only be taught to more mature children.
In the UK, primary school algebra enjoyed a brief renaissance in the 1950s and 1960s, but fell out of general practice, although it has recently been trialled in schools by mathematicians at Exeter and Plymouth universities.
Ruth Butler, of Ashby Church of England primary school in Leicestershire, one of the pilot schools, said: "The kids are totally inspired by it. They grasped ideas they wouldn't usually. Kids who weren't very good with numbers suddenly shone. It's a very powerful tool."