The CAS Registry Mumber 19759-94-5 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 1,9,7,5 and 9 respectively; the second part has 2 digits, 9 and 4 respectively. Calculate Digit Verification of CAS Registry Number 19759-94: (7*1)+(6*9)+(5*7)+(4*5)+(3*9)+(2*9)+(1*4)=165 165 % 10 = 5 So 19759-94-5 is a valid CAS Registry Number.