The CAS Registry Mumber 70975-69-8 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 7,0,9,7 and 5 respectively; the second part has 2 digits, 6 and 9 respectively. Calculate Digit Verification of CAS Registry Number 70975-69: (7*7)+(6*0)+(5*9)+(4*7)+(3*5)+(2*6)+(1*9)=158 158 % 10 = 8 So 70975-69-8 is a valid CAS Registry Number.