The CAS Registry Mumber 112537-61-8 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,1,2,5,3 and 7 respectively; the second part has 2 digits, 6 and 1 respectively. Calculate Digit Verification of CAS Registry Number 112537-61: (8*1)+(7*1)+(6*2)+(5*5)+(4*3)+(3*7)+(2*6)+(1*1)=98 98 % 10 = 8 So 112537-61-8 is a valid CAS Registry Number.