The CAS Registry Mumber 366006-72-6 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 3,6,6,0,0 and 6 respectively; the second part has 2 digits, 7 and 2 respectively. Calculate Digit Verification of CAS Registry Number 366006-72: (8*3)+(7*6)+(6*6)+(5*0)+(4*0)+(3*6)+(2*7)+(1*2)=136 136 % 10 = 6 So 366006-72-6 is a valid CAS Registry Number.