The CAS Registry Mumber 1201935-99-0 includes 10 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 7 digits, 1,2,0,1,9,3 and 5 respectively; the second part has 2 digits, 9 and 9 respectively. Calculate Digit Verification of CAS Registry Number 1201935-99: (9*1)+(8*2)+(7*0)+(6*1)+(5*9)+(4*3)+(3*5)+(2*9)+(1*9)=130 130 % 10 = 0 So 1201935-99-0 is a valid CAS Registry Number.