The CAS Registry Mumber 90826-12-3 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 9,0,8,2 and 6 respectively; the second part has 2 digits, 1 and 2 respectively. Calculate Digit Verification of CAS Registry Number 90826-12: (7*9)+(6*0)+(5*8)+(4*2)+(3*6)+(2*1)+(1*2)=133 133 % 10 = 3 So 90826-12-3 is a valid CAS Registry Number.