The CAS Registry Mumber 92901-61-6 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 9,2,9,0 and 1 respectively; the second part has 2 digits, 6 and 1 respectively. Calculate Digit Verification of CAS Registry Number 92901-61: (7*9)+(6*2)+(5*9)+(4*0)+(3*1)+(2*6)+(1*1)=136 136 % 10 = 6 So 92901-61-6 is a valid CAS Registry Number.