The CAS Registry Mumber 2893-61-0 includes 7 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 4 digits, 2,8,9 and 3 respectively; the second part has 2 digits, 6 and 1 respectively. Calculate Digit Verification of CAS Registry Number 2893-61: (6*2)+(5*8)+(4*9)+(3*3)+(2*6)+(1*1)=110 110 % 10 = 0 So 2893-61-0 is a valid CAS Registry Number.