Abacus made of the natural material RE-Wood® with 100 balls in the colours yellow, green, dark blue, red, turquoise, light blue, grey, orange, brown and purple.
Can be ideally combined with our system working materials, as the individual place values are coordinated with each other.
All of the Wissner items follow the same scheme:
One = yellow
Tens = green
Hundreds = blue
Thousands = red etc.