The CAS Registry Mumber 2392-67-8 includes 7 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 4 digits, 2,3,9 and 2 respectively; the second part has 2 digits, 6 and 7 respectively. Calculate Digit Verification of CAS Registry Number 2392-67: (6*2)+(5*3)+(4*9)+(3*2)+(2*6)+(1*7)=88 88 % 10 = 8 So 2392-67-8 is a valid CAS Registry Number.