Calculation of Science marks

1st: Written paper marks is /100 >> must change to /90
--> divide by 100 times 90

2nd: Pract marks is /15 >> must change to /10
--> divide by 15 times 10

Then add the two marks = SA2 SC

Overall marks for SC for the whole 2007 year:
SA1 : 30%
SA2 : 70%