The CAS Registry Mumber 119778-57-3 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,1,9,7,7 and 8 respectively; the second part has 2 digits, 5 and 7 respectively. Calculate Digit Verification of CAS Registry Number 119778-57: (8*1)+(7*1)+(6*9)+(5*7)+(4*7)+(3*8)+(2*5)+(1*7)=173 173 % 10 = 3 So 119778-57-3 is a valid CAS Registry Number.