The CAS Registry Mumber 137760-96-4 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,3,7,7,6 and 0 respectively; the second part has 2 digits, 9 and 6 respectively. Calculate Digit Verification of CAS Registry Number 137760-96: (8*1)+(7*3)+(6*7)+(5*7)+(4*6)+(3*0)+(2*9)+(1*6)=154 154 % 10 = 4 So 137760-96-4 is a valid CAS Registry Number.