The CAS Registry Mumber 1142192-28-6 includes 10 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 7 digits, 1,1,4,2,1,9 and 2 respectively; the second part has 2 digits, 2 and 8 respectively. Calculate Digit Verification of CAS Registry Number 1142192-28: (9*1)+(8*1)+(7*4)+(6*2)+(5*1)+(4*9)+(3*2)+(2*2)+(1*8)=116 116 % 10 = 6 So 1142192-28-6 is a valid CAS Registry Number.