Geometric Hierarchy Number Cards

The Geometric Hierarchy Number Cards give the wooden hierarchy solids their written names, from the single unit up to the largest category in the set. Laid out in a row on a mat, smallest first, they let the child read the growing line of zeros in one movement of the eye. Laying a card beside its solid, the child sees written and built at the same moment that each step is ten times the one before it. A card set against the wrong solid leaves another one without a partner, so the mistake shows itself by the end of the row. Used with the geometric hierarchy in the decimal system work from about three years.