The CAS Registry Mumber 87092-41-9 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 8,7,0,9 and 2 respectively; the second part has 2 digits, 4 and 1 respectively. Calculate Digit Verification of CAS Registry Number 87092-41: (7*8)+(6*7)+(5*0)+(4*9)+(3*2)+(2*4)+(1*1)=149 149 % 10 = 9 So 87092-41-9 is a valid CAS Registry Number.