The CAS Registry Mumber 88043-73-6 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 8,8,0,4 and 3 respectively; the second part has 2 digits, 7 and 3 respectively. Calculate Digit Verification of CAS Registry Number 88043-73: (7*8)+(6*8)+(5*0)+(4*4)+(3*3)+(2*7)+(1*3)=146 146 % 10 = 6 So 88043-73-6 is a valid CAS Registry Number.