The CAS Registry Mumber 862-52-2 includes 6 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 3 digits, 8,6 and 2 respectively; the second part has 2 digits, 5 and 2 respectively. Calculate Digit Verification of CAS Registry Number 862-52: (5*8)+(4*6)+(3*2)+(2*5)+(1*2)=82 82 % 10 = 2 So 862-52-2 is a valid CAS Registry Number.