The CAS Registry Mumber 90024-26-3 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 9,0,0,2 and 4 respectively; the second part has 2 digits, 2 and 6 respectively. Calculate Digit Verification of CAS Registry Number 90024-26: (7*9)+(6*0)+(5*0)+(4*2)+(3*4)+(2*2)+(1*6)=93 93 % 10 = 3 So 90024-26-3 is a valid CAS Registry Number.