The CAS Registry Mumber 84540-14-7 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 8,4,5,4 and 0 respectively; the second part has 2 digits, 1 and 4 respectively. Calculate Digit Verification of CAS Registry Number 84540-14: (7*8)+(6*4)+(5*5)+(4*4)+(3*0)+(2*1)+(1*4)=127 127 % 10 = 7 So 84540-14-7 is a valid CAS Registry Number.