The CAS Registry Mumber 68569-88-0 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 6,8,5,6 and 9 respectively; the second part has 2 digits, 8 and 8 respectively. Calculate Digit Verification of CAS Registry Number 68569-88: (7*6)+(6*8)+(5*5)+(4*6)+(3*9)+(2*8)+(1*8)=190 190 % 10 = 0 So 68569-88-0 is a valid CAS Registry Number.