The CAS Registry Mumber 75893-04-8 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 7,5,8,9 and 3 respectively; the second part has 2 digits, 0 and 4 respectively. Calculate Digit Verification of CAS Registry Number 75893-04: (7*7)+(6*5)+(5*8)+(4*9)+(3*3)+(2*0)+(1*4)=168 168 % 10 = 8 So 75893-04-8 is a valid CAS Registry Number.