Apps cpa calculator help needed

[dragonz]

hi guys im a college student..currently im doing one assignment based on CGPA calculator for my university...So i already created the interface..Im using spinner to include credit hours such as (1,2,3,4) and for grade (A+,A,A-,B+,B,B-,C+,C,C-,E,F)..Im dont know how to proceed with the calculation...can anyone help me to code on this?? i need your help badly...

formula is credit hour X grade value

here i give you value for each grade that used in my university
A+=4.00
A=4.00
A-=3.75
B+=3.50
B=3.00
B-=2.75
C+=2.50
C=2.25
C-=2.00
E=1.00
F=0.0

can any one help me in this?? here i give you sample of my interface..you can create your own..then ill manipulate it..

 

[Aluxian]

That's easy, how come you created this nice layout but you don't know how to calculate... Or maybe you've only created the layout but didn't code anything, am I right?

For completed hours you add each value in the first spinner (that would be 25 in your screenshot) then calculate the cgpa for each row then make an average and show it in current cgpa. I'm starting to think you know these things and only need help coding...