The CAS Registry Mumber 84182-45-6 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 8,4,1,8 and 2 respectively; the second part has 2 digits, 4 and 5 respectively. Calculate Digit Verification of CAS Registry Number 84182-45: (7*8)+(6*4)+(5*1)+(4*8)+(3*2)+(2*4)+(1*5)=136 136 % 10 = 6 So 84182-45-6 is a valid CAS Registry Number.