The CAS Registry Mumber 37832-54-5 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 3,7,8,3 and 2 respectively; the second part has 2 digits, 5 and 4 respectively. Calculate Digit Verification of CAS Registry Number 37832-54: (7*3)+(6*7)+(5*8)+(4*3)+(3*2)+(2*5)+(1*4)=135 135 % 10 = 5 So 37832-54-5 is a valid CAS Registry Number.