The CAS Registry Mumber 106894-34-2 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,0,6,8,9 and 4 respectively; the second part has 2 digits, 3 and 4 respectively. Calculate Digit Verification of CAS Registry Number 106894-34: (8*1)+(7*0)+(6*6)+(5*8)+(4*9)+(3*4)+(2*3)+(1*4)=142 142 % 10 = 2 So 106894-34-2 is a valid CAS Registry Number.