The CAS Registry Mumber 622785-64-2 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 6,2,2,7,8 and 5 respectively; the second part has 2 digits, 6 and 4 respectively. Calculate Digit Verification of CAS Registry Number 622785-64: (8*6)+(7*2)+(6*2)+(5*7)+(4*8)+(3*5)+(2*6)+(1*4)=172 172 % 10 = 2 So 622785-64-2 is a valid CAS Registry Number.