The CAS Registry Mumber 1093786-43-6 includes 10 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 7 digits, 1,0,9,3,7,8 and 6 respectively; the second part has 2 digits, 4 and 3 respectively. Calculate Digit Verification of CAS Registry Number 1093786-43: (9*1)+(8*0)+(7*9)+(6*3)+(5*7)+(4*8)+(3*6)+(2*4)+(1*3)=186 186 % 10 = 6 So 1093786-43-6 is a valid CAS Registry Number.