The CAS Registry Mumber 141354-16-7 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,4,1,3,5 and 4 respectively; the second part has 2 digits, 1 and 6 respectively. Calculate Digit Verification of CAS Registry Number 141354-16: (8*1)+(7*4)+(6*1)+(5*3)+(4*5)+(3*4)+(2*1)+(1*6)=97 97 % 10 = 7 So 141354-16-7 is a valid CAS Registry Number.