The CAS Registry Mumber 108098-07-3 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,0,8,0,9 and 8 respectively; the second part has 2 digits, 0 and 7 respectively. Calculate Digit Verification of CAS Registry Number 108098-07: (8*1)+(7*0)+(6*8)+(5*0)+(4*9)+(3*8)+(2*0)+(1*7)=123 123 % 10 = 3 So 108098-07-3 is a valid CAS Registry Number.