Scotland's first national schools strike since the 1980s is taking place with a one-day walkout by teaching staff.
Pupils at nearly every primary and secondary school and many council nurseries are affected by the industrial action over pay.
A revised pay offer on Tuesday was rejected as "insulting" by unions.
But Education Secretary Shirley-Anne Somerville said their demands for a 10% pay rise were "unaffordable".
A new pay offer from employer Cosla - which would have seen rises of up to 6.85% for the lowest paid - was fair, Ms Somerville said.