Adding machine for teaching children to count and add comprises parallel paths in which balls are placed with sliders, which have holes matched to the ball diameters, arranged perpendicular to the paths

摘要

Mechanical adding machine especially for use in elementary or primary schools to help children to learn to add has a number of parallel separate paths in which balls of matching diameter are placed. Sliders with openings through which one ball will pass are provided and arranged perpendicular to the paths. Counting or adding is achieved by moving balls one at a time through the holes.