The CAS Registry Mumber 101038-22-6 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,0,1,0,3 and 8 respectively; the second part has 2 digits, 2 and 2 respectively. Calculate Digit Verification of CAS Registry Number 101038-22: (8*1)+(7*0)+(6*1)+(5*0)+(4*3)+(3*8)+(2*2)+(1*2)=56 56 % 10 = 6 So 101038-22-6 is a valid CAS Registry Number.