The CAS Registry Mumber 136860-08-7 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,3,6,8,6 and 0 respectively; the second part has 2 digits, 0 and 8 respectively. Calculate Digit Verification of CAS Registry Number 136860-08: (8*1)+(7*3)+(6*6)+(5*8)+(4*6)+(3*0)+(2*0)+(1*8)=137 137 % 10 = 7 So 136860-08-7 is a valid CAS Registry Number.