The CAS Registry Mumber 86145-90-6 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 8,6,1,4 and 5 respectively; the second part has 2 digits, 9 and 0 respectively. Calculate Digit Verification of CAS Registry Number 86145-90: (7*8)+(6*6)+(5*1)+(4*4)+(3*5)+(2*9)+(1*0)=146 146 % 10 = 6 So 86145-90-6 is a valid CAS Registry Number.