The CAS Registry Mumber 51782-10-6 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 5,1,7,8 and 2 respectively; the second part has 2 digits, 1 and 0 respectively. Calculate Digit Verification of CAS Registry Number 51782-10: (7*5)+(6*1)+(5*7)+(4*8)+(3*2)+(2*1)+(1*0)=116 116 % 10 = 6 So 51782-10-6 is a valid CAS Registry Number.