The CAS Registry Mumber 9059-09-0 includes 7 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 4 digits, 9,0,5 and 9 respectively; the second part has 2 digits, 0 and 9 respectively. Calculate Digit Verification of CAS Registry Number 9059-09: (6*9)+(5*0)+(4*5)+(3*9)+(2*0)+(1*9)=110 110 % 10 = 0 So 9059-09-0 is a valid CAS Registry Number.