The CAS Registry Mumber 282092-89-1 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 2,8,2,0,9 and 2 respectively; the second part has 2 digits, 8 and 9 respectively. Calculate Digit Verification of CAS Registry Number 282092-89: (8*2)+(7*8)+(6*2)+(5*0)+(4*9)+(3*2)+(2*8)+(1*9)=151 151 % 10 = 1 So 282092-89-1 is a valid CAS Registry Number.