The CAS Registry Mumber 72060-18-5 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 7,2,0,6 and 0 respectively; the second part has 2 digits, 1 and 8 respectively. Calculate Digit Verification of CAS Registry Number 72060-18: (7*7)+(6*2)+(5*0)+(4*6)+(3*0)+(2*1)+(1*8)=95 95 % 10 = 5 So 72060-18-5 is a valid CAS Registry Number.