The CAS Registry Mumber 35690-03-0 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 3,5,6,9 and 0 respectively; the second part has 2 digits, 0 and 3 respectively. Calculate Digit Verification of CAS Registry Number 35690-03: (7*3)+(6*5)+(5*6)+(4*9)+(3*0)+(2*0)+(1*3)=120 120 % 10 = 0 So 35690-03-0 is a valid CAS Registry Number.