The CAS Registry Mumber 374687-94-2 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 3,7,4,6,8 and 7 respectively; the second part has 2 digits, 9 and 4 respectively. Calculate Digit Verification of CAS Registry Number 374687-94: (8*3)+(7*7)+(6*4)+(5*6)+(4*8)+(3*7)+(2*9)+(1*4)=202 202 % 10 = 2 So 374687-94-2 is a valid CAS Registry Number.