The CAS Registry Mumber 1227579-04-5 includes 10 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 7 digits, 1,2,2,7,5,7 and 9 respectively; the second part has 2 digits, 0 and 4 respectively. Calculate Digit Verification of CAS Registry Number 1227579-04: (9*1)+(8*2)+(7*2)+(6*7)+(5*5)+(4*7)+(3*9)+(2*0)+(1*4)=165 165 % 10 = 5 So 1227579-04-5 is a valid CAS Registry Number.