1. An abacus (plurals abacuses or abaci), also called a counting frame, is a calculating tool for performing arithmetical processes, often constructed as a wooden frame with beads sliding on wires. The user, called an abacist, slides counters by hand on rods or in grooves.

Абак Абак (математика) — счётная доска , применявшаяся для арифметических вычислений .

2. The spoon with groove is attached to the end face of the hollow cylinder, a screw-shaped slot is made in the hollow cylinder wall and a roller, which is fastened to the body with a handle by means of a pin, is accommodated in said slot.

Ложка с пазом прикреплена к торцу полого цилиндра, а в стенке полого цилиндра выполнена винтовая прорезь, в которой размещен ролик, прикрепленный штифтом к корпусу с ручкой.