The CAS Registry Mumber 857828-65-0 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 8,5,7,8,2 and 8 respectively; the second part has 2 digits, 6 and 5 respectively. Calculate Digit Verification of CAS Registry Number 857828-65: (8*8)+(7*5)+(6*7)+(5*8)+(4*2)+(3*8)+(2*6)+(1*5)=230 230 % 10 = 0 So 857828-65-0 is a valid CAS Registry Number.