The CAS Registry Mumber 160651-07-0 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,6,0,6,5 and 1 respectively; the second part has 2 digits, 0 and 7 respectively. Calculate Digit Verification of CAS Registry Number 160651-07: (8*1)+(7*6)+(6*0)+(5*6)+(4*5)+(3*1)+(2*0)+(1*7)=110 110 % 10 = 0 So 160651-07-0 is a valid CAS Registry Number.