The CAS Registry Mumber 749261-39-0 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 7,4,9,2,6 and 1 respectively; the second part has 2 digits, 3 and 9 respectively. Calculate Digit Verification of CAS Registry Number 749261-39: (8*7)+(7*4)+(6*9)+(5*2)+(4*6)+(3*1)+(2*3)+(1*9)=190 190 % 10 = 0 So 749261-39-0 is a valid CAS Registry Number.