The CAS Registry Mumber 10075-40-8 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 1,0,0,7 and 5 respectively; the second part has 2 digits, 4 and 0 respectively. Calculate Digit Verification of CAS Registry Number 10075-40: (7*1)+(6*0)+(5*0)+(4*7)+(3*5)+(2*4)+(1*0)=58 58 % 10 = 8 So 10075-40-8 is a valid CAS Registry Number.