The CAS Registry Mumber 100462-34-8 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,0,0,4,6 and 2 respectively; the second part has 2 digits, 3 and 4 respectively. Calculate Digit Verification of CAS Registry Number 100462-34: (8*1)+(7*0)+(6*0)+(5*4)+(4*6)+(3*2)+(2*3)+(1*4)=68 68 % 10 = 8 So 100462-34-8 is a valid CAS Registry Number.