Three have a book-sharing scheme, where each school buys a group of textbooks on a particular topic and shares with the others in rotation. The idea, prompted by education officers and headteachers, was implemented after schools found that they were struggling to buy resources.
Carmyllie, Colliston and Arbirlot primaries in Arbroath clubbed together to buy more than pound;800 worth of science textbooks. "We have agreed on a three-year rolling programme between the three schools, with the resources doing a yearly move," Leila Martin, the Colliston head, said.
"It's a new initiative and we only got the books about six weeks ago, so it is still very much in its infancy. But it's looking very promising. I am getting positive feedback and I am enjoying working with the heads from the others schools."
Tarfside primary in Brechin is one of 11 schools in the cluster associated with Webster's High in Kirriemuir which have been co-operating. Rhona Kirkpatrick, the Tarfside head, had found it "virtually impossible" to buy the whole range of resources for every area of the curriculum.
"We have purchased things like a skeleton and the model of an ear - things you don't need every day but which are useful for teaching science," she said. "These are boxed up and stored at the secondary school and everybody has a list of the resources available to them."
Sharing resources to teach science at primary level is something Angus is particularly encouraging rural primaries to do. Mary Logue, staff tutor in science, said: "Big schools can buy resources at cheaper prices as things like books often come in packs of 10, for example, when a small school may only need a few.
"Jointly purchasing and sharing books means one school might study energy, another electricity and the forces and they will use them on a rotating basis. It's a clever use of sharing the resources they have."
Schools have been working together in other ways. Two weeks ago, pupils from the three Arbroath schools took part in a science fair at Carmyllie primary. Pupils from P1-P7 all got to sample science in many of its guises, stimulating their interest while forging links between the schools.
"It was a fun day for the kids and good for teachers' professional development," Leila Martin, head of Colliston primary, said. It will be the first of many activities to be planned jointly.