Money in the Roman slang
Baiocco of 1795 by Pius VI Rather famous are the various names that were used to give to certain determined sums of money in lire, and consequently to some banknotes and coins.
From the sonnets by Belli there are frequent quotations of papal coins that the populace indicated as bajocchi and pavoli.
Present in the more recent Roman daily life, for small purchases, were the bags.
A sack (rarely used in the singular) corresponded to the sum of 1000 lire.
Going up in value, we meet the shield, or the banknote (therefore the value) corresponding to 5000 lire (in short, five bags = ‘no shield).
It should be mentioned that the shield was the Italian name of the 5 lire coin until the early decades of the twentieth century.
The term “piotta” indicates the number one hundred and was used to indicate the 100 lire coin or the 100,000 lira banknote. The use of the same name hardly created problems, given the difference between the two digits: the context swept any doubt.
With the term piotta various sums could be named, from 50.000 lire to 900.000, respectively saying “half piotta” or “nine piottes”.
For higher numbers the term mijone or mijardo was used more directly and rationally, nothing more than “million” or “billion” in Italian (even if the term “Un Bonaventura” was sometimes heard to define the million lire referring to the fictional character “Mister Bonaventura” who at the end of his exploits always received a one million check as a prize).
With the advent of the euro, some of these Roman terms remained in common use.
A lot means 1 euro, a shield means 5 euro and a piotta 100 euro.
The older generations, however, continue to use these terms referring to the equivalent in euro of their old meaning in lire (for example: a piotta can also indicate 50 euros, or 100,000 lire).
It must be said that in the Roman slang, in particular modern, the term “piotta” does not have a purely economic reference, but it can also mean going very quickly, in this case it is in fact a verb, “piottare” or going quickly in the sense of both metaphorical material: for example, “‘is machina piotta’ na figure” or “this car goes (or can go) very fast”,  and therefore quickly reaches and exceeds 100 kilometers per hour.
The advent of the euro (declined in the plural to euro ) has significantly reduced the use of these terms.
However, in the popular language there are still numerous references to the lira (in a largely derogatory sense: “nun c’ho ‘na lira”, “nun vale’ na lira”, “robba da du ‘lire” …) and to the money ( in the slang form “quatrino”).