The CAS Registry Mumber 124232-68-4 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,2,4,2,3 and 2 respectively; the second part has 2 digits, 6 and 8 respectively. Calculate Digit Verification of CAS Registry Number 124232-68: (8*1)+(7*2)+(6*4)+(5*2)+(4*3)+(3*2)+(2*6)+(1*8)=94 94 % 10 = 4 So 124232-68-4 is a valid CAS Registry Number.