The CAS Registry Mumber 47607-26-1 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 4,7,6,0 and 7 respectively; the second part has 2 digits, 2 and 6 respectively. Calculate Digit Verification of CAS Registry Number 47607-26: (7*4)+(6*7)+(5*6)+(4*0)+(3*7)+(2*2)+(1*6)=131 131 % 10 = 1 So 47607-26-1 is a valid CAS Registry Number.