The CAS Registry Mumber 344752-67-6 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 3,4,4,7,5 and 2 respectively; the second part has 2 digits, 6 and 7 respectively. Calculate Digit Verification of CAS Registry Number 344752-67: (8*3)+(7*4)+(6*4)+(5*7)+(4*5)+(3*2)+(2*6)+(1*7)=156 156 % 10 = 6 So 344752-67-6 is a valid CAS Registry Number.