The CAS Registry Mumber 120260-35-7 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,2,0,2,6 and 0 respectively; the second part has 2 digits, 3 and 5 respectively. Calculate Digit Verification of CAS Registry Number 120260-35: (8*1)+(7*2)+(6*0)+(5*2)+(4*6)+(3*0)+(2*3)+(1*5)=67 67 % 10 = 7 So 120260-35-7 is a valid CAS Registry Number.