The CAS Registry Mumber 83584-38-7 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 8,3,5,8 and 4 respectively; the second part has 2 digits, 3 and 8 respectively. Calculate Digit Verification of CAS Registry Number 83584-38: (7*8)+(6*3)+(5*5)+(4*8)+(3*4)+(2*3)+(1*8)=157 157 % 10 = 7 So 83584-38-7 is a valid CAS Registry Number.