The CAS Registry Mumber 40035-23-2 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 4,0,0,3 and 5 respectively; the second part has 2 digits, 2 and 3 respectively. Calculate Digit Verification of CAS Registry Number 40035-23: (7*4)+(6*0)+(5*0)+(4*3)+(3*5)+(2*2)+(1*3)=62 62 % 10 = 2 So 40035-23-2 is a valid CAS Registry Number.