The CAS Registry Mumber 62505-85-5 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 6,2,5,0 and 5 respectively; the second part has 2 digits, 8 and 5 respectively. Calculate Digit Verification of CAS Registry Number 62505-85: (7*6)+(6*2)+(5*5)+(4*0)+(3*5)+(2*8)+(1*5)=115 115 % 10 = 5 So 62505-85-5 is a valid CAS Registry Number.