In todays lesson, I added the final grade system to my markbook. This gives the grade of the student overall of all the assessments.
These are the final grade marks. It is out of 160.

0-F
30-E
60-D
85-C
100-B
160-A

Today i also finished the instructions tab. This is what the instructions now say:

Welcome to Markbook Marjorie. To create a new class. Simply click the New class button which is placed on the home page and the template page.
To view what the template looks like click the template button which is located on the home page.
Once created a new class, Replace the student information where they are titled. Then add all the marks. Everything should already be premade. This determines already what the grades are and the total marks are.
To change the grading system. At the very right of the markbook, there should be a series of tables which state what mark gives what grade. If u wish to change the grade, simply replace the numbers so that the grades will change. Please ensure that F- is still 0 and A - is the mark that the assessment is out of.
To view the class averages for each assessment scroll to the right, this will show the average of each assessment and the highest and the lowest mark for each assessment.
The arrows under each title heading allow u to view the highest marks, the lowest marks and specific marks. For the grading system the arrows allow you to view the students that got specific grades.

In todays lesson, i also designed my markbook. to make it look more presentable to users.
I added pictures. To make it more appealing.