Seitenansicht des Dozenten, der etwas mit Kreide auf die Tafel schreibt - Stockfoto & -bild

Grey hair professor correcting something at blackboard

Senior lecturer writing something on blackboard and showing one finger up

Rear view of senior lecturer writing something on blackboard with piece of chalk

Pensive grey hair professor standing at blackboard with piece of chalk

Grey hair professor drawing with piece of chalk at blackboard

Portrait of a dedicated Maths teacher explaining a theory against greenboard during class in a modern school or university

Grey hair professor correcting something at blackboard

Senior lecturer writing something on blackboard and showing one finger up

Rear view of senior lecturer writing something on blackboard with piece of chalk

Pensive grey hair professor standing at blackboard with piece of chalk

Grey hair professor drawing with piece of chalk at blackboard

Grey hair professor holding piece of chalk and looking at blackboard

Smiling senior lecturer standing in classroom and looking at camera

Grey hair professor pointing on something with pencil on blackboard

Grey hair professor looking at blackboard