The CAS Registry Mumber 3152-73-6 includes 7 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 4 digits, 3,1,5 and 2 respectively; the second part has 2 digits, 7 and 3 respectively. Calculate Digit Verification of CAS Registry Number 3152-73: (6*3)+(5*1)+(4*5)+(3*2)+(2*7)+(1*3)=66 66 % 10 = 6 So 3152-73-6 is a valid CAS Registry Number.