Decoding the secret math of Roman letters

sonia Roman Abacus Arithmetic

Slide the bronze, slide the bronze / We do the math with no pen in our hands.

sonia Seven Latin letters combine to represent values in the Roman numeral system.

sonia Smooth pebbles represent Roman numerals arranged to form mathematical calculations

Fun Fact

Calculi counting: Scribes used small limestone pebbles called calculi to calculate on boards, which gave us our modern word 'calculate.'

Glossary

abacus (noun)
A manual device used for making mathematical calculations by sliding counters along rods or in grooves. Ancient Romans performed arithmetic using portable bronze boards, only writing down the final results as numerals.

Gossip

Could you survive doing math with pebbles?

Quiz

How did Roman tax collectors keep track of temporary calculations before writing final tallies?

Quiz

Which mathematical concept is missing from Roman numerals that makes column-based addition impossible?

Quiz

In the Roman hand abacus, what did a bead in the short upper slot represent?

Quiz

What metal was the rare, highly portable Roman hand abacus typically made of?

Quiz

Why did medieval European merchants prefer Roman numerals over Arabic numerals for ledger books?

Quiz

What does the Latin word 'calculi,' which inspired our word 'calculate,' actually mean?

Quiz

What was the name of the large checkered table used in medieval England for tax calculations?

Quiz

Which mathematical operation was the most difficult to perform using only written Roman numerals?