Grades can be calculated several different ways. 1st Class GradeBook 
supports all different calculation methods. You must be sure you have 
selected the method that is appropriate for you. Here are the 
different methods:

To demonstrate we will use the following example and calculate the 
grade using each method. Let's say our ficticious course has two 
grading categories (activity types). Labs & Tests. Our ficticious 
student, John, has acheived the following grades:

Labs: 20/30, 60/100
Tests: 80/100, 15/20

1) Points
Using the points system John's grade would be calculated:

(20+60+80+15) / (30+100+100+20) 
= 175 / 250 
= 70.0%

This feature can be turned on by going to the CLASS screen and 
setting the "Activity Type Weighting" to "Use Points" for each 
category (activity type) you have listed.

2) Weighted Categories
Weighted categories require that each category (activity type) must 
have an associated weighting. This weighting is often expressed 
as a percentage although 1st Class GradeBook will allow you to 
use any weighting scheme you like. In our example let's say that 
Tests are weighted at 60% and Labs are weighted at 40%. Here is 
how John's grade would be calculated with this grading scheme:

((20+60) / (30+100) * 40 ) + ((80+15) / (100+20) * 60) 
= ((80 / 130) * 40) + ((95/120) * 60)
= (0.6154% * 40) + (0.7917 * 60)
= 24.62 + 47.50
= 72.1%

This feature can be turned on by going to the CLASS screen and 
entering in a number into the weight column for each category 
(activity type). Most teachers will use weights that total 100 
although it is not a requirement.

3) Equally weighted activities within a category (activity type)
This option usually only makes sense with weighted categories. 
Please read the weighted categories example above before 
proceeding with this example. We will use the same weighting 
with Tests weighted at 60% and Labs weighted at 40%. Here is 
how John's grade would be calculated using this grading scheme.

((((20/30) + (60/100)) / 2) * 40) + ((((80/100) + (15/20)) / 2) * 60)
= (((0.6667 + 0.6000) / 2) * 40) + (((0.8000+0.7500) / 2) * 60)
= (0.6334 * 40) + (0.7750 * 60)
= 25.34 + 46.5
= 71.8%

This feature can be turned on by going to the SETUP screen and 
selecting the option titled "Equally weight all activities within 
an activity type (category)".

-----------------------------------------------------------------

In short, when setting the different possible grading calculation
methods you should adjust the following settings:

a)  In the CLASS screen the Activity Type Weighting can be set to
a weight (often out of 100) or to "Use Points"
 
b)  In the SETUP screen the option to "Equally weight all activities
within an activity type (category)" can be turned on or off.  This is
NOT usually used in conjuction with "Use Points".

------------------------------------------------------------------
If you are having a problem with grade calculations you should print
out a "Student Detailed Report" and use it to follow along with the
example above.  Try changing each setting and then re-running the
report until the grades are calculated in the manner you wish.

If the problem still persists please follow these instructions:
http://1st-class-software.com/cgi-bin/fom.cgi?file=39