The CAS Registry Mumber 34927-48-5 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 3,4,9,2 and 7 respectively; the second part has 2 digits, 4 and 8 respectively. Calculate Digit Verification of CAS Registry Number 34927-48: (7*3)+(6*4)+(5*9)+(4*2)+(3*7)+(2*4)+(1*8)=135 135 % 10 = 5 So 34927-48-5 is a valid CAS Registry Number.