The CAS Registry Mumber 51152-47-7 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 5,1,1,5 and 2 respectively; the second part has 2 digits, 4 and 7 respectively. Calculate Digit Verification of CAS Registry Number 51152-47: (7*5)+(6*1)+(5*1)+(4*5)+(3*2)+(2*4)+(1*7)=87 87 % 10 = 7 So 51152-47-7 is a valid CAS Registry Number.