One of my math teachers has the following question:

 

I am trying to create a question that could give partial credit for an unsimplified answer.

The question is about slope.  The student is given a graph to count the slope.  The completely correct answer is -4 but a student also might put -4/1.  Another example might be completely correct  1/2 but partial correct 4/8.

 

I want to give half credit for -4/1 because the student is counting the slope correctly but not simplifying.  Is this possible?

 

I tried to list an alternate answer and reduce the points to 0.5 but when tested it still marked correct.  If I list penalty points it marks it all wrong.

 

Please advise and see pictures below.