Money, Moolah, Cash
Brazil's current currency is the Real (plural: Reais), and its decimal form is centavo(s) - the Portuguese word for cents. It's symbol is R$.
In Portuguese "real" can mean both "royal" and "real", depending on the situation.
In Brazil the use of commas and decimals are the opposite of that in North America (but the same as in most of Europe, I believe).
So if a book costs costs five Reais and twenty five centavos it would look like this: R$ 5,25
Brazil has 6 bank note values and 5 coin values.
All coins (5, 10, 25, and 50 cents as well as a R$ 1 coin) are commonly used.
The most commonly used bank notes are R$ 2, R$ 5, R$ 10, R$20, and R$ 50.
Just like English has its slang for money (moolah, cash, etc), Portuguese has it too. The most common are "grana" and "dim dim". Other slangs include "cobre" (copper), "prata" (silver), "Mango" (somewhat equivalent to the use of "bucks" or "quid"), and "bufunfa".
"Trocado" is slang for small change.
"Troco" is is the change you receive when you're buying something, so depending on what you're buying the change can very well be big.