The CAS Registry Mumber 37982-11-9 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 3,7,9,8 and 2 respectively; the second part has 2 digits, 1 and 1 respectively. Calculate Digit Verification of CAS Registry Number 37982-11: (7*3)+(6*7)+(5*9)+(4*8)+(3*2)+(2*1)+(1*1)=149 149 % 10 = 9 So 37982-11-9 is a valid CAS Registry Number.