The CAS Registry Mumber 98011-36-0 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 9,8,0,1 and 1 respectively; the second part has 2 digits, 3 and 6 respectively. Calculate Digit Verification of CAS Registry Number 98011-36: (7*9)+(6*8)+(5*0)+(4*1)+(3*1)+(2*3)+(1*6)=130 130 % 10 = 0 So 98011-36-0 is a valid CAS Registry Number.