The CAS Registry Mumber 118759-70-9 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,1,8,7,5 and 9 respectively; the second part has 2 digits, 7 and 0 respectively. Calculate Digit Verification of CAS Registry Number 118759-70: (8*1)+(7*1)+(6*8)+(5*7)+(4*5)+(3*9)+(2*7)+(1*0)=159 159 % 10 = 9 So 118759-70-9 is a valid CAS Registry Number.