Does this sound right?

[Boo Boo]

Went to our local casino last night and played nl for the first time.

The blinds were 1/2 maximum buy in is $80.

$5 chips are the norm with $1 chips being the exception.
Anyway, people were calling preflop by just throwing in a $5 chip.

I thought this was odd as I would assume this would be a raise. So I ask what the minimum raise is preflop to which the answer is $4.

This confused the [censored] out of me. Then it got worse as people would say raise to $5 and others who wouldn't have heard the raise would just throw in a $5 chip to call the $2 blind.

There were no questions regarding it but it forced me to ask practically every hand "is the bet $2?"

Is this normal procedure?