The CAS Registry Mumber 136136-02-2 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,3,6,1,3 and 6 respectively; the second part has 2 digits, 0 and 2 respectively. Calculate Digit Verification of CAS Registry Number 136136-02: (8*1)+(7*3)+(6*6)+(5*1)+(4*3)+(3*6)+(2*0)+(1*2)=102 102 % 10 = 2 So 136136-02-2 is a valid CAS Registry Number.