The CAS Registry Mumber 82883-61-2 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 8,2,8,8 and 3 respectively; the second part has 2 digits, 6 and 1 respectively. Calculate Digit Verification of CAS Registry Number 82883-61: (7*8)+(6*2)+(5*8)+(4*8)+(3*3)+(2*6)+(1*1)=162 162 % 10 = 2 So 82883-61-2 is a valid CAS Registry Number.