Undergraduate first-year courses are often mandatory for students in a variety of majors and degrees. Many students view these core courses as of little interest and relevance, which is associated with lack of motivation for study and can lead to cheating. Contract cheating in text-based is difficult to detect and prove. Contract cheating in numerical-calculation-based assessments is even harder to detect and prove. This paper discusses how unique identifying information can be incorporated into numerical assessments and how unique data sets can be used to both detect and prove contract cheating. Finally, some measures to discourage contract cheating are discussed.