The CAS Registry Mumber 84395-19-7 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 8,4,3,9 and 5 respectively; the second part has 2 digits, 1 and 9 respectively. Calculate Digit Verification of CAS Registry Number 84395-19: (7*8)+(6*4)+(5*3)+(4*9)+(3*5)+(2*1)+(1*9)=157 157 % 10 = 7 So 84395-19-7 is a valid CAS Registry Number.