(note: automatic translation; please, allow few days to review it)
The beginning of the Byzantine coinage makes him go up again to the monetary reform of Anastasio in 498, that the last monetary system of the based Roman empire reformed on the coin in bronze called nummus and the gold coin called solid.
The nummo was a coin in bronze extremely small, with a diameter of around 8-10 mms, uncomfortable to use since they also asked for an elevated number for small exchanges.
The new coin in bronze was made as multiples of this coin as the coins from the 40, 20, 10 and 5 nummis. On the front of this coin an image was represented stylized of the emperor, while the reverse brought the value of the coin according to the Greek system of numeration (M=40, K=20, I=10, E=5). The value of 40 nummis, as follis was pointed out.
The term nummo is also used as synonym of sesterzio.