The CAS Registry Mumber 142292-43-1 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,4,2,2,9 and 2 respectively; the second part has 2 digits, 4 and 3 respectively. Calculate Digit Verification of CAS Registry Number 142292-43: (8*1)+(7*4)+(6*2)+(5*2)+(4*9)+(3*2)+(2*4)+(1*3)=111 111 % 10 = 1 So 142292-43-1 is a valid CAS Registry Number.