Insegnante maschio pulire equazioni matematiche con spugna dalla lavagna in classe - Foto e immagini stock

Male teacher in formal wear wiping mathematical equations with sponge in classroom

Male teacher in formal wear writing equation on chalkboard in maths class

Caucasian teacher look blackboard and think about problem solution

Senior chemistry professor writing on the board while having a chalk and blackboard lecture

Female professor showing equations in classroom

Teacher pointing at equations in classroom with student

Female teacher looking at camera and pointing with finger at mathematical equation on chalkboard in class

Cropped view of male student wiping mathematical equations with sponge in classroom

Crumpled paper balls flying at frightened female teacher in classroom with chalkboard on background

Female teacher in glasses sitting at desk and pointing at laptop with blank screen in classroom

Crumpled paper balls flying at frightened female teacher in classroom with chalkboard on background

Beautiful female teacher with wooden pointer explaining mathematical equations in classroom

Female teacher sitting at computer desk, holding glasses and having headache in class