The CAS Registry Mumber 73483-61-1 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 7,3,4,8 and 3 respectively; the second part has 2 digits, 6 and 1 respectively. Calculate Digit Verification of CAS Registry Number 73483-61: (7*7)+(6*3)+(5*4)+(4*8)+(3*3)+(2*6)+(1*1)=141 141 % 10 = 1 So 73483-61-1 is a valid CAS Registry Number.