The CAS Registry Mumber 141874-27-3 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,4,1,8,7 and 4 respectively; the second part has 2 digits, 2 and 7 respectively. Calculate Digit Verification of CAS Registry Number 141874-27: (8*1)+(7*4)+(6*1)+(5*8)+(4*7)+(3*4)+(2*2)+(1*7)=133 133 % 10 = 3 So 141874-27-3 is a valid CAS Registry Number.