The CAS Registry Mumber 1325-12-8 includes 7 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 4 digits, 1,3,2 and 5 respectively; the second part has 2 digits, 1 and 2 respectively. Calculate Digit Verification of CAS Registry Number 1325-12: (6*1)+(5*3)+(4*2)+(3*5)+(2*1)+(1*2)=48 48 % 10 = 8 So 1325-12-8 is a valid CAS Registry Number.