The CAS Registry Mumber 134867-67-7 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,3,4,8,6 and 7 respectively; the second part has 2 digits, 6 and 7 respectively. Calculate Digit Verification of CAS Registry Number 134867-67: (8*1)+(7*3)+(6*4)+(5*8)+(4*6)+(3*7)+(2*6)+(1*7)=157 157 % 10 = 7 So 134867-67-7 is a valid CAS Registry Number.