Can I pay for something with coins only? For example, can I pay for a $1 chocolate bar with 100 pennies?
This is actually covered by legislation. The Currency Act sets out limits on a tender of payment in coin:
forty dollars if the denomination is two dollars or greater but does not exceed ten dollars;
twenty-five dollars if the denomination is one dollar;
ten dollars if the denomination is ten cents or greater but less than one dollar;
five dollars if the denomination is five cents; and
twenty-five cents if the denomination is one cent.
But, as always, agreement between the parties will determine what is acceptable. For instance, stores and banks are often glad to accept coinage beyond these amounts, particularly when it is wrapped and labelled.