South Australia's public school teachers have voted to strike next week.

Teachers want more pay and better conditions for their “increasingly complex” classrooms.

It is the second time teachers have held industrial action in less than 12 months, following a half-day strike and rally in November last year.

The State Government has offered to lift wages by 2.35 per cent per year until 2022, but the Australian Education Union (AEU) says it wants an agreement on learning conditions and workloads as well.

The union is also calling for a 3.5 per cent increase in pay, bringing the state in line with national standards.

AEU SA president Howard Spreadbury said it is not all about the money.

“The union is looking for an increase in the level of resourcing that the Government is putting on the table to address complexity,” he told the ABC.

“It's not just the quantum of money, it's the mechanism for how that money is allocated.

“We want the resource to be able to find its way into the classroom to support the teacher and the students in that class, to assist the learning of students, to assist the increasingly complex workload of teachers.

“We would anticipate that a significant majority of over 500 schools and preschools as well would be participating in the action on Monday.”

SA Treasurer Rob Lucas says the strikes will cause chaos.

“We are disappointed, but perhaps not surprised, that the union bosses from the AEU have got their wish and proceeded down the path of maximum disruption and chaos for parents, grandparents and students in the final week of term,” Mr Lucas said.

“While we respect their right to industrial action, we have made it quite clear that no amount of chanting, waving placards and singing John Farnham songs is going to make money magically appear in the budget.

“The Government has put forward an exceptionally fair and reasonable offer, one that provides a 2.35 per cent per annum pay rise until May 2022 and millions in additional funding for schools with higher levels of complexity, for highly accomplished and lead teachers and country incentives.”