What do the ridges on edge of a quarter stand for?
I don’t think they stand for anything. Ridges were put around the edges of coins (when coins were made of valuable metals like silver and gold) to prevent people from shaving small amounts from the edges of a lot of coins and melting down the shavings to sell, while passing off the modified coins as still having their face value. Some countries put different patterns of ridges around the edges so that blind people can tell the denomination of the coin.
