The CAS Registry Mumber 41634-29-1 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 4,1,6,3 and 4 respectively; the second part has 2 digits, 2 and 9 respectively. Calculate Digit Verification of CAS Registry Number 41634-29: (7*4)+(6*1)+(5*6)+(4*3)+(3*4)+(2*2)+(1*9)=101 101 % 10 = 1 So 41634-29-1 is a valid CAS Registry Number.