The CAS Registry Mumber 81295-35-4 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 8,1,2,9 and 5 respectively; the second part has 2 digits, 3 and 5 respectively. Calculate Digit Verification of CAS Registry Number 81295-35: (7*8)+(6*1)+(5*2)+(4*9)+(3*5)+(2*3)+(1*5)=134 134 % 10 = 4 So 81295-35-4 is a valid CAS Registry Number.