Problem with calculating an excel formula from one sheet to another Help

So what I am trying to do is in B7, create a formula to calculate the first's students percentage score on their homework by adding all of the values in that student's row located on the Homework worksheet. Then dividing the sum by the total number of homework points starting in row 7 of the homework sheet. This is what I have in the worksheet and what I have tried but am coming up with a #Value!....what am I doing wrong? A little help with this would be appreciated..


This is what I put in
=Homework!$D$9:$O$9/Homework!$D$7:$O$7

Homework
Student 20%
Banks, Michelle

Students Score
35 20 18 19 20 20 18 18 36 18 20 20 38 77

Points
40 20 20 20 20 20 20 20 40 20 20 20 40 80

Geeze I think I am loosing my head; that is what I forgot, thank you for your help