Novice question: grain level

Hello,
Please can you clarify something about the grain level in dimensions.

Suppose you have a fact table, where each fact has a sale_number, and a sale_quantity, let's say. You also have a dimension table: Location, with the following hierarchy: continent -> country -> city. The grain in this case is the city. However, obviously, in each city there can be many sales.
Then, you browse the cube using the Location dimension, you'll see Continent/Country/City and in front of it there will be sum(sale_quantity) of all sales in the city.
My question is, if you wanna have a further browsing level, where the grain is a sale (So when you browse down to city, you wanna browse further and see quantity of each sale by itself), should you include the sale as a grain level in the dimension Location for that to be possible ?

Thank you.

In the same topic, how do you 'browse by' fields of the fact table.
I've seen people in some instances create a dimension table based on the fact table, and then creating an attribute corresponding to each column in the fact table that they wanna use as a browsing dimension.
Is this the proper way to do it ?

thank you.

you dont need to store the sales number in dimension table
you already have it in your fact table i.e.. sales number which is a Degenerate Dimension

ok, but in this case you won't be able to browse down to the sale_number when you explore the cube...

add fact table as a dimension table and relationship type should be a Fact Relationship Type