Reliability Test - Cronbach


Through my quasi-experiment in math classroom, I have made pre and post-exams. Each exam had 3-4 open-ended questions (not MCQ). Each question had a different score. Each exam is summed up over 10.
I was asked to do the reliability test using spss for each exam.
The question is, should unify the question scores for the reliability test to work? or I keep question scores as written on the exam?

This is a sample from my SPSS for the first exam:

ID Q1 Q2 Q3 Q4
1 2.5 3 1 1
2 2 2.25 0.5 2

Please advise.