The CAS Registry Mumber 2483-54-7 includes 7 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 4 digits, 2,4,8 and 3 respectively; the second part has 2 digits, 5 and 4 respectively. Calculate Digit Verification of CAS Registry Number 2483-54: (6*2)+(5*4)+(4*8)+(3*3)+(2*5)+(1*4)=87 87 % 10 = 7 So 2483-54-7 is a valid CAS Registry Number.