How to calculate sum of the fields that will be reflected for every row entry??

Question

Probably, the title might not give you the correct view on the question that I want to ask but, I can describe my question. Well, I have an
Excel sheet for attendance where in I have different columns
for 3 subjects (subject1, subject2, subject3) and a
total column. I also have another column named as Student ID.
I would like to write a formula for the total column where, when I enter the number of classes attended in every subject column for each student present in every row, then the total column is reflected with the sum of no.of classes attended in every subject
for each student automatically.
How can I achieve this? I am looking forward for any help. I am a beginner.
Ex: Excel sheet
Student ID | Subject1 | Subject2 | Subject3 | Total
1               
|     2        
|       3      
|       4       |   
9
2                |     3        
|       5      
|      2       
|   1
The total column should be reflected with the sum of values under subject1, subject2, subject3 fields automatically for every row. How to do it?
Thank you,
Kaushik.

Answer 1

In the first empty cell of the row of Student 1, enter a formula like
=SUM(B2:D2)
where column B is headed Subject 1 and column D is headed Subject 3, then copy down to match your student list.
Then below the last row of column B, enter the formula
=SUM(B2:BXXX)
where 2 is the row of Student 1, and XXX is the row number of the row above the formula, then copy across to match.