The CAS Registry Mumber 107244-61-1 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 1 respectively. Calculate Digit Verification of CAS Registry Number 107244-61: (8*1)+(7*0)+(6*7)+(5*2)+(4*4)+(3*4)+(2*6)+(1*1)=101 101 % 10 = 1 So 107244-61-1 is a valid CAS Registry Number.