Title

Blackboard with calculations frame

Caption

Blackboard with calculations frame

Date

Jun 13, 2018

Credit line

Photo12/imageBROKER

Reference

BRK23G23_209

License type

Rights managed

Available size

68,7Mb (3,4Mb) / 20,0in x 13,3in / 6000 x 4000 (300dpi)

Keywords

blackboard calculate calculate calculation chalk class class classroom deserted educational institution formula geometry knowledge learn lesson mathematics old retro school science scientific symbolic training triangle triangular vintage