The CAS Registry Mumber 35600-61-4 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 3,5,6,0 and 0 respectively; the second part has 2 digits, 6 and 1 respectively. Calculate Digit Verification of CAS Registry Number 35600-61: (7*3)+(6*5)+(5*6)+(4*0)+(3*0)+(2*6)+(1*1)=94 94 % 10 = 4 So 35600-61-4 is a valid CAS Registry Number.