The CAS Registry Mumber 1552-37-0 includes 7 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 4 digits, 1,5,5 and 2 respectively; the second part has 2 digits, 3 and 7 respectively. Calculate Digit Verification of CAS Registry Number 1552-37: (6*1)+(5*5)+(4*5)+(3*2)+(2*3)+(1*7)=70 70 % 10 = 0 So 1552-37-0 is a valid CAS Registry Number.