The CAS Registry Mumber 77969-37-0 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 7,7,9,6 and 9 respectively; the second part has 2 digits, 3 and 7 respectively. Calculate Digit Verification of CAS Registry Number 77969-37: (7*7)+(6*7)+(5*9)+(4*6)+(3*9)+(2*3)+(1*7)=200 200 % 10 = 0 So 77969-37-0 is a valid CAS Registry Number.