The CAS Registry Mumber 19798-62-0 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 1,9,7,9 and 8 respectively; the second part has 2 digits, 6 and 2 respectively. Calculate Digit Verification of CAS Registry Number 19798-62: (7*1)+(6*9)+(5*7)+(4*9)+(3*8)+(2*6)+(1*2)=170 170 % 10 = 0 So 19798-62-0 is a valid CAS Registry Number.