The CAS Registry Mumber 37679-18-8 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 3,7,6,7 and 9 respectively; the second part has 2 digits, 1 and 8 respectively. Calculate Digit Verification of CAS Registry Number 37679-18: (7*3)+(6*7)+(5*6)+(4*7)+(3*9)+(2*1)+(1*8)=158 158 % 10 = 8 So 37679-18-8 is a valid CAS Registry Number.