The CAS Registry Mumber 1027251-58-6 includes 10 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 7 digits, 1,0,2,7,2,5 and 1 respectively; the second part has 2 digits, 5 and 8 respectively. Calculate Digit Verification of CAS Registry Number 1027251-58: (9*1)+(8*0)+(7*2)+(6*7)+(5*2)+(4*5)+(3*1)+(2*5)+(1*8)=116 116 % 10 = 6 So 1027251-58-6 is a valid CAS Registry Number.