The CAS Registry Mumber 107244-66-6 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,0,7,2,4 and 4 respectively; the second part has 2 digits, 6 and 6 respectively. Calculate Digit Verification of CAS Registry Number 107244-66: (8*1)+(7*0)+(6*7)+(5*2)+(4*4)+(3*4)+(2*6)+(1*6)=106 106 % 10 = 6 So 107244-66-6 is a valid CAS Registry Number.