The CAS Registry Mumber 57536-72-8 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 5,7,5,3 and 6 respectively; the second part has 2 digits, 7 and 2 respectively. Calculate Digit Verification of CAS Registry Number 57536-72: (7*5)+(6*7)+(5*5)+(4*3)+(3*6)+(2*7)+(1*2)=148 148 % 10 = 8 So 57536-72-8 is a valid CAS Registry Number.