The CAS Registry Mumber 1140923-99-4 includes 10 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 7 digits, 1,1,4,0,9,2 and 3 respectively; the second part has 2 digits, 9 and 9 respectively. Calculate Digit Verification of CAS Registry Number 1140923-99: (9*1)+(8*1)+(7*4)+(6*0)+(5*9)+(4*2)+(3*3)+(2*9)+(1*9)=134 134 % 10 = 4 So 1140923-99-4 is a valid CAS Registry Number.