The CAS Registry Mumber 1174429-88-9 includes 10 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 7 digits, 1,1,7,4,4,2 and 9 respectively; the second part has 2 digits, 8 and 8 respectively. Calculate Digit Verification of CAS Registry Number 1174429-88: (9*1)+(8*1)+(7*7)+(6*4)+(5*4)+(4*2)+(3*9)+(2*8)+(1*8)=169 169 % 10 = 9 So 1174429-88-9 is a valid CAS Registry Number.