The CAS Registry Mumber 93741-43-6 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 9,3,7,4 and 1 respectively; the second part has 2 digits, 4 and 3 respectively. Calculate Digit Verification of CAS Registry Number 93741-43: (7*9)+(6*3)+(5*7)+(4*4)+(3*1)+(2*4)+(1*3)=146 146 % 10 = 6 So 93741-43-6 is a valid CAS Registry Number.