The CAS Registry Mumber 534600-59-4 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 5,3,4,6,0 and 0 respectively; the second part has 2 digits, 5 and 9 respectively. Calculate Digit Verification of CAS Registry Number 534600-59: (8*5)+(7*3)+(6*4)+(5*6)+(4*0)+(3*0)+(2*5)+(1*9)=134 134 % 10 = 4 So 534600-59-4 is a valid CAS Registry Number.