When using GradeBook for Google Sheets and Classroom you have a number of different ways to calculate the final mark for a student.

Here are some of the most common methods:

**GradeBook Type: Standard using a Weighted Average**
With this type of GradeBook all **assignments are weighted relative to each other**. This is useful when you have a mixture of large and small assignments and don't want to worry about how many marks each are worth.

**Here is an example:**
Assignment 1: 25/30
Assignment 2: 10/20

In a total points system you would just average the marks:

(25 + 10) / (30 + 20 ) = 35/50 = 70%)

However lets say you want Assignment 1 to be worth three times as much as assignment 2 then you would enter the following as weights in your GradeBook:

Assignment 1: 25/30 weight: 3 Assignment 2: 10/20 weight: 1

This calculation would be:

( (25/30)*3 + (10/20)*1 ) / (3 + 1) = ( (0.833)*3 + (0.5) ) / 4 = 3/4 = 75%

That's a 5% difference from a total points calculation! The reason is because the student did better on assignment 1 and it is worth three times as much as assignment 2.

**GradeBook Type: Standard using a Total Points System**
This is a common system to use, just add up all the points and just average the marks. To do this in GradeBook just enter the weights as the total marks such as:

Assignment 1: 25/30 weight: 30 Assignment 2: 15/20 weight: 20

**GradeBook Type: Category Based**

With this type of GradeBook each **category is assigned a weight of the total course** and assignments within each category are weighted relative to each other.

A common category based system is: 10% Quizzes 30% Tests 30% Assignments 30% Exam

The sum of all the categories would make up 100% of the course. Now for each assessment you would assign a category and an assessment weight. For the assessment weight you can use any of the methods mentioned earlier.

So in this system an assessment has a category to which is belongs (and the category has a weight of the total course) and a weight of how much it is worth within the category, compared to other assignments also in the category.

I hope this makes sense, tricky stuff!