A large amount of money can weight a lot. This can be an issue for banks, governments and money launderers.
United States currency has a fixed size and all bills weight about 1 gram.
Minor variation in weight can occur due to:
(1) variation of cutting currency sheets
(2) torn corners
(3) accumulated debris
weight of an amount of money in one denomination in grams =
= (amount of money) / (denomination)
amount of money for a given weight of money =
= (weight in grams) * (value of denomination)