The CAS Registry Mumber 140427-89-0 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,4,0,4,2 and 7 respectively; the second part has 2 digits, 8 and 9 respectively. Calculate Digit Verification of CAS Registry Number 140427-89: (8*1)+(7*4)+(6*0)+(5*4)+(4*2)+(3*7)+(2*8)+(1*9)=110 110 % 10 = 0 So 140427-89-0 is a valid CAS Registry Number.