The CAS Registry Mumber 120853-22-7 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,2,0,8,5 and 3 respectively; the second part has 2 digits, 2 and 2 respectively. Calculate Digit Verification of CAS Registry Number 120853-22: (8*1)+(7*2)+(6*0)+(5*8)+(4*5)+(3*3)+(2*2)+(1*2)=97 97 % 10 = 7 So 120853-22-7 is a valid CAS Registry Number.