The CAS Registry Mumber 5267-23-2 includes 7 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 4 digits, 5,2,6 and 7 respectively; the second part has 2 digits, 2 and 3 respectively. Calculate Digit Verification of CAS Registry Number 5267-23: (6*5)+(5*2)+(4*6)+(3*7)+(2*2)+(1*3)=92 92 % 10 = 2 So 5267-23-2 is a valid CAS Registry Number.