The CAS Registry Mumber 37478-12-9 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 3,7,4,7 and 8 respectively; the second part has 2 digits, 1 and 2 respectively. Calculate Digit Verification of CAS Registry Number 37478-12: (7*3)+(6*7)+(5*4)+(4*7)+(3*8)+(2*1)+(1*2)=139 139 % 10 = 9 So 37478-12-9 is a valid CAS Registry Number.