The CAS Registry Mumber 41710-26-3 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 4,1,7,1 and 0 respectively; the second part has 2 digits, 2 and 6 respectively. Calculate Digit Verification of CAS Registry Number 41710-26: (7*4)+(6*1)+(5*7)+(4*1)+(3*0)+(2*2)+(1*6)=83 83 % 10 = 3 So 41710-26-3 is a valid CAS Registry Number.