The CAS Registry Mumber 120208-25-5 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,2,0,2,0 and 8 respectively; the second part has 2 digits, 2 and 5 respectively. Calculate Digit Verification of CAS Registry Number 120208-25: (8*1)+(7*2)+(6*0)+(5*2)+(4*0)+(3*8)+(2*2)+(1*5)=65 65 % 10 = 5 So 120208-25-5 is a valid CAS Registry Number.