The CAS Registry Mumber 126993-10-0 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,2,6,9,9 and 3 respectively; the second part has 2 digits, 1 and 0 respectively. Calculate Digit Verification of CAS Registry Number 126993-10: (8*1)+(7*2)+(6*6)+(5*9)+(4*9)+(3*3)+(2*1)+(1*0)=150 150 % 10 = 0 So 126993-10-0 is a valid CAS Registry Number.