The CAS Registry Mumber 140926-90-5 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,4,0,9,2 and 6 respectively; the second part has 2 digits, 9 and 0 respectively. Calculate Digit Verification of CAS Registry Number 140926-90: (8*1)+(7*4)+(6*0)+(5*9)+(4*2)+(3*6)+(2*9)+(1*0)=125 125 % 10 = 5 So 140926-90-5 is a valid CAS Registry Number.