The CAS Registry Mumber 35959-84-3 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 3,5,9,5 and 9 respectively; the second part has 2 digits, 8 and 4 respectively. Calculate Digit Verification of CAS Registry Number 35959-84: (7*3)+(6*5)+(5*9)+(4*5)+(3*9)+(2*8)+(1*4)=163 163 % 10 = 3 So 35959-84-3 is a valid CAS Registry Number.