20 Arithmetic bead string
Arithmetic Bead String (approx. 45 cm) with 20 balls, which are threaded in steps of 5 on a tear-resistant, stretchable cord. The balls are made of RE-Plastic® and have a diameter of 10 mm. When the string is pulled, the light ball lock is released and all the beads slip back together.
Since the balls have the exact diameter of 1 cm, these are also suitable for calculating and measuring.
Packed in cardboard box with instructions in german language.
This could also be interesting:
count forwards and backwards from 1 to 20 grasp quantities at a glance decompose quantities (7 decomposed into e.g. 5 and 2) count in steps...