The CAS Registry Mumber 1569-04-6 includes 7 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 4 digits, 1,5,6 and 9 respectively; the second part has 2 digits, 0 and 4 respectively. Calculate Digit Verification of CAS Registry Number 1569-04: (6*1)+(5*5)+(4*6)+(3*9)+(2*0)+(1*4)=86 86 % 10 = 6 So 1569-04-6 is a valid CAS Registry Number.