The CAS Registry Mumber 134508-26-2 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,3,4,5,0 and 8 respectively; the second part has 2 digits, 2 and 6 respectively. Calculate Digit Verification of CAS Registry Number 134508-26: (8*1)+(7*3)+(6*4)+(5*5)+(4*0)+(3*8)+(2*2)+(1*6)=112 112 % 10 = 2 So 134508-26-2 is a valid CAS Registry Number.