The CAS Registry Mumber 151602-27-6 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,5,1,6,0 and 2 respectively; the second part has 2 digits, 2 and 7 respectively. Calculate Digit Verification of CAS Registry Number 151602-27: (8*1)+(7*5)+(6*1)+(5*6)+(4*0)+(3*2)+(2*2)+(1*7)=96 96 % 10 = 6 So 151602-27-6 is a valid CAS Registry Number.