The CAS Registry Mumber 83472-52-0 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 8,3,4,7 and 2 respectively; the second part has 2 digits, 5 and 2 respectively. Calculate Digit Verification of CAS Registry Number 83472-52: (7*8)+(6*3)+(5*4)+(4*7)+(3*2)+(2*5)+(1*2)=140 140 % 10 = 0 So 83472-52-0 is a valid CAS Registry Number.