The CAS Registry Mumber 1447231-20-0 includes 10 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 7 digits, 1,4,4,7,2,3 and 1 respectively; the second part has 2 digits, 2 and 0 respectively. Calculate Digit Verification of CAS Registry Number 1447231-20: (9*1)+(8*4)+(7*4)+(6*7)+(5*2)+(4*3)+(3*1)+(2*2)+(1*0)=140 140 % 10 = 0 So 1447231-20-0 is a valid CAS Registry Number.