Quick Answer:The Decimal Abacus Model is a 7-column spike abacus for teaching base-10 place value and decimals, with columns running from thousands to thousandths and colour-coded beads for each column.
Last updated: 19 October 2026
Key Features
7 vertical spikes covering thousands down to thousandths.
Colour-coded counter beads, at least 9 per column.
Shows place values from whole numbers to thousandths.
Desktop size, typically a 250mm x 80mm footprint.
Technical Specifications
Specification
Value
Columns
7 vertical spikes (thousands to thousandths)
Beads
Colour-coded, 9 per column minimum
Footprint
Typical 250mm x 80mm
Base material
High-impact ABS polymer or sealed engineered wood
How It Is Used
Pupils build numbers by placing beads on the spikes, each spike standing for one place value either side of the decimal point. Adding, removing and exchanging beads between neighbouring spikes shows how decimal addition, subtraction and regrouping work.
Frequently Asked Questions
Which place values does the Decimal Abacus Model cover?
Its 7 vertical spike columns run from thousands down to thousandths, so both whole-number and decimal place values can be shown.