The CAS Registry Mumber 138846-09-0 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,3,8,8,4 and 6 respectively; the second part has 2 digits, 0 and 9 respectively. Calculate Digit Verification of CAS Registry Number 138846-09: (8*1)+(7*3)+(6*8)+(5*8)+(4*4)+(3*6)+(2*0)+(1*9)=160 160 % 10 = 0 So 138846-09-0 is a valid CAS Registry Number.