The CAS Registry Mumber 84850-35-1 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 8,4,8,5 and 0 respectively; the second part has 2 digits, 3 and 5 respectively. Calculate Digit Verification of CAS Registry Number 84850-35: (7*8)+(6*4)+(5*8)+(4*5)+(3*0)+(2*3)+(1*5)=151 151 % 10 = 1 So 84850-35-1 is a valid CAS Registry Number.