The CAS Registry Mumber 85253-99-2 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 8,5,2,5 and 3 respectively; the second part has 2 digits, 9 and 9 respectively. Calculate Digit Verification of CAS Registry Number 85253-99: (7*8)+(6*5)+(5*2)+(4*5)+(3*3)+(2*9)+(1*9)=152 152 % 10 = 2 So 85253-99-2 is a valid CAS Registry Number.