The CAS Registry Mumber 111822-82-3 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,1,1,8,2 and 2 respectively; the second part has 2 digits, 8 and 2 respectively. Calculate Digit Verification of CAS Registry Number 111822-82: (8*1)+(7*1)+(6*1)+(5*8)+(4*2)+(3*2)+(2*8)+(1*2)=93 93 % 10 = 3 So 111822-82-3 is a valid CAS Registry Number.