congratulations babalicious, this is your 100th apend about you holiday to Florida (only joking).
The sales tax is not huge, but as other have said, it is added at the till.
So if you see an item at say 5 dollars and 99 cents, when you get to the till it is something like 6 dollars and 10 cents.
The annoying thing is it means you keep getting loads of change.
If the item was 5 dollars and 99 cents, and you gave them 10 dollars, you would get 4 dollars and 1 cent back so only 1 coin.
But if it is 6 dollars and 10 cents you get 3 dollars and 90 cents back, so loads of coins.
by the way, all the dollar bills (1 dollar up to 100 dollars) are the SAME SIZE and SAME COLOR.
If you plan to give someone a 1 dollar tip it is very easy to give them a 100 dollar tip, So when you hand over notes, check what the amount is on the note.