Calculating GPA with a long integer field

[JoJoM]

In student records, I need to store "credits attempted" versus "credits earned" in order to calculate GPA. This has usually worked but the school has a new credit points system in the medical/dental where the "credits attempted" are, for example, 4.70. (Most are 3, 4, or other whole numbers) I have a lookup table (course master) which stores credit hours as long integer. I have an update query that looks up credits attempted in the course master. The 4.70 keeps coming over to the student table as "5". I have tried changing number types and decimal places. It is not a space issue. any ideas?

[June7]

The field type in student table must be Double type.

What do you mean by 'keeps coming over' - coming from where? Where does 4.70 come from?

[JoeM]

It is fine if the underlying fields used in your calculations (i.e. hours/credits) are stored as Long Integer, but not your calculated field. Long Integers do not allow for any decimal places.
How/where is this calculation done?
Are you trying to store this calculation in a field after calculating it?

[JoJoM]

1. The table Course_Master has a course ID and a field for "credit hours." Up to now, these have all been whole numbers.
2. When a student takes a course, I create a detail row in a table called Student-Course. It stores student ID and Course ID. There is a field for "credits attempted," which is blank upon creation of the field.
3. When final grades are entered, I run an update query that updates the credits attempted field in Student-Course based on the value stored in Course master. e
UPDATE [Course Master] INNER JOIN [Student-Course] ON [Course Master].[Course Code] = [Student-Course].[Course Code] SET [Student-Course].[Credits Attempted] = [Course Master]![Credit Hours]
WHERE ((([Student-Course].[Credits Attempted]) Is Null));

4. The Course Master stores 4.70 credit hours for this one dental course, but when I run the update query, the record for the student who took that course now has a value of "5" in the Credits attempted field, not 4.70.

I THINK i might have solved it by setting the data types as double, and 4 decimal places, in both tables.