The CAS Registry Mumber 144192-64-3 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,4,4,1,9 and 2 respectively; the second part has 2 digits, 6 and 4 respectively. Calculate Digit Verification of CAS Registry Number 144192-64: (8*1)+(7*4)+(6*4)+(5*1)+(4*9)+(3*2)+(2*6)+(1*4)=123 123 % 10 = 3 So 144192-64-3 is a valid CAS Registry Number.