The CAS Registry Mumber 1197981-08-0 includes 10 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 7 digits, 1,1,9,7,9,8 and 1 respectively; the second part has 2 digits, 0 and 8 respectively. Calculate Digit Verification of CAS Registry Number 1197981-08: (9*1)+(8*1)+(7*9)+(6*7)+(5*9)+(4*8)+(3*1)+(2*0)+(1*8)=210 210 % 10 = 0 So 1197981-08-0 is a valid CAS Registry Number.