The CAS Registry Mumber 884846-74-6 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 8,8,4,8,4 and 6 respectively; the second part has 2 digits, 7 and 4 respectively. Calculate Digit Verification of CAS Registry Number 884846-74: (8*8)+(7*8)+(6*4)+(5*8)+(4*4)+(3*6)+(2*7)+(1*4)=236 236 % 10 = 6 So 884846-74-6 is a valid CAS Registry Number.