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