They called on Wednesday for Basic Education Minister Angie Motshekga and her director general Bobby Soobrayan to resign.
They carried placards reading: "Angie has failed to deal with overcrowding in schools for delivery of quality education", and "Use your R480-million of biometric system to eradicate mud schools. Pay the rural allowance".
Sadtu members were in high spirits as they sang struggle songs. Sadtu KwaZulu-Natal deputy secretary Nomarashiya Caluza said teachers were not on a go-slow, but on a work-to-rule protest.
This meant teachers worked for only seven hours, and did not teach morning and Saturday classes.
Caluza said the union was planning on stepping up its work-to-rule action nationally, with two marches planned in Pretoria and Cape Town next week.
She said that when a teacher took action against its employer, pupils would be affected. The union was stepping up its campaign because Motshekga was in denial, Caluza said.
"Since the minister came to power in 2009, she has done nothing to improve education."
Some of the union's grievances were that Grade R teachers were not being paid enough, Grade 12 examination markers had not received an increase in salaries, and some schools were without the necessary resources to ensure quality education. – Sapa