The CAS Registry Mumber 51673-60-0 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 5,1,6,7 and 3 respectively; the second part has 2 digits, 6 and 0 respectively. Calculate Digit Verification of CAS Registry Number 51673-60: (7*5)+(6*1)+(5*6)+(4*7)+(3*3)+(2*6)+(1*0)=120 120 % 10 = 0 So 51673-60-0 is a valid CAS Registry Number.