The CAS Registry Mumber 123296-50-4 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,2,3,2,9 and 6 respectively; the second part has 2 digits, 5 and 0 respectively. Calculate Digit Verification of CAS Registry Number 123296-50: (8*1)+(7*2)+(6*3)+(5*2)+(4*9)+(3*6)+(2*5)+(1*0)=114 114 % 10 = 4 So 123296-50-4 is a valid CAS Registry Number.