The CAS Registry Mumber 133552-00-8 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,3,3,5,5 and 2 respectively; the second part has 2 digits, 0 and 0 respectively. Calculate Digit Verification of CAS Registry Number 133552-00: (8*1)+(7*3)+(6*3)+(5*5)+(4*5)+(3*2)+(2*0)+(1*0)=98 98 % 10 = 8 So 133552-00-8 is a valid CAS Registry Number.