The CAS Registry Mumber 1576240-05-5 includes 10 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 7 digits, 1,5,7,6,2,4 and 0 respectively; the second part has 2 digits, 0 and 5 respectively. Calculate Digit Verification of CAS Registry Number 1576240-05: (9*1)+(8*5)+(7*7)+(6*6)+(5*2)+(4*4)+(3*0)+(2*0)+(1*5)=165 165 % 10 = 5 So 1576240-05-5 is a valid CAS Registry Number.