Ausgeschnittene Ansicht eines Mannes mit Kreide, der Zahlen auf Tafel schreibt - Stockfoto & -bild

Cropped view of man writing numbers with chalk on blackboard

School board with inscriptions on it close-up

A closeup shot of a blackboard with equations

Hand writing on blackboard in class room

Primary school concept. Young kid studying mathematics, doing sum on chalkboard.

School board with inscriptions on it close-up

Cropped view of african american teacher writing on chalkboard

Cropped image of senior professor pointing on something with pencil on blackboard

Panoramic shot of schoolchild holding chalk near chalkboard on green

Preteen schoolgirl pointing with pen at mathematic equations on chalkboard

Cropped image of professor drawing with piece of chalk at blackboard

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

Arithmetic numbers on green school chalkboard