Arithmetic

Fingers can operate as a mechanical computer: your fingers allow you to count in the decimal, twelve and sexagesimal system.

These reproductions of tesserae (= counting discs) show a finger position at the front and a Roman numeral at the back. Various ancient sources indicate the Romans counted with their fingers in the decimal (= ten-digit) system.

Until well into the Middle Ages, traders could negotiate prices with each other using this finger technique, without having to know each other's language.

Applied mathematics on a crate of Duvel: follow the logic of mathematical modelling of numbers.

A walk through a modern-day department store learns us that most stacking techniques lend themselves to a specific modelling of numbers.

The Roman abacus was a simple mechanical computer with surprising capabilities.

For units, the base 10 system was used, for fractions the base 12 system.

Around the 3rd century BC, a new coin came into use in the Roman Republic: the 'aes grave' (heavy bronze). The depicted coin is a quadrans, the three dots on both sides indicate that this coin is 3/12 of the value of 1 'as'. This Roman 'as' was the reference unit of the currency at that time (a similar concept as the 1 euro now in Europe).