The CAS Registry Mumber 345585-70-8 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 3,4,5,5,8 and 5 respectively; the second part has 2 digits, 7 and 0 respectively. Calculate Digit Verification of CAS Registry Number 345585-70: (8*3)+(7*4)+(6*5)+(5*5)+(4*8)+(3*5)+(2*7)+(1*0)=168 168 % 10 = 8 So 345585-70-8 is a valid CAS Registry Number.