The CAS Registry Mumber 33835-04-0 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 3,3,8,3 and 5 respectively; the second part has 2 digits, 0 and 4 respectively. Calculate Digit Verification of CAS Registry Number 33835-04: (7*3)+(6*3)+(5*8)+(4*3)+(3*5)+(2*0)+(1*4)=110 110 % 10 = 0 So 33835-04-0 is a valid CAS Registry Number.